Review markdown.md and edit notes

doc/user/markdown.md

@@ -78,9 +78,7 @@ character of the top list item (`C` in this case):
    - dark
    - milk
 
-NOTE: **Note:**
-We flag any significant differences between Redcarpet and CommonMark
-  Markdown in this document.
+We flag any significant differences between Redcarpet and CommonMark Markdown in this document.
 
 If you have a large volume of Markdown files, it can be tedious to determine
 if they display correctly or not. You can use the
@@ -126,7 +124,7 @@ changing how standard Markdown is used:
 
 ### Colors
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#colors).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#colors).
 
 It's possible to have color written in HEX, RGB, or HSL format rendered with a color
 indicator.
@@ -235,7 +233,7 @@ To make PlantUML available in GitLab, a GitLab administrator needs to enable it
 
 ### Emoji
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#emoji).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#emoji).
 
 ```markdown
 Sometimes you want to :monkey: around a bit and add some :star2: to your :speech_balloon:. Well we have a gift for you:
@@ -259,13 +257,14 @@ If you're new to this, don't be <img src="https://gitlab.com/gitlab-org/gitlab-f
 
 Consult the [Emoji Cheat Sheet](https://www.webfx.com/tools/emoji-cheat-sheet/) for a list of all supported emoji codes. <img src="https://gitlab.com/gitlab-org/gitlab-foss/raw/master/app/assets/images/emoji/thumbsup.png" width="20px" height="20px" style="display:inline;margin:0">
 
-NOTE: **Note:**
+#### Emoji and your OS
+
 The emoji example above uses hard-coded images for this documentation. The emoji,
 when rendered within GitLab, may appear different depending on the OS and browser used.
 
-Most emoji are natively supported on macOS, Windows, iOS, Android, and fall back on image-based emoji where there is no support.
+Most emoji are natively supported on macOS, Windows, iOS, Android, and fall back on image-based
+emoji where there is no support.
 
-NOTE: **Note:**
 On Linux, you can download [Noto Color Emoji](https://www.google.com/get/noto/help/emoji/)
 to get full native emoji support. Ubuntu 18.04 (like many modern Linux distributions) has
 this font installed by default.
@@ -335,7 +334,7 @@ $example = array(
 
 ### Inline diff
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#inline-diff).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#inline-diff).
 
 With inline diff tags you can display `{+ additions +}` or `[- deletions -]`.
 
@@ -374,7 +373,7 @@ backslash `\`, otherwise the diff highlight don't render correctly:
 
 ### Math
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#math).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#math).
 
 It's possible to have math written with LaTeX syntax rendered using [KaTeX](https://github.com/KaTeX/KaTeX).
 
@@ -402,8 +401,7 @@ a^2+b^2=c^2
 
 _Be advised that KaTeX only supports a [subset](https://katex.org/docs/supported.html) of LaTeX._
 
-NOTE: **Note:**
-This also works for the Asciidoctor `:stem: latexmath`. For details see
+This also works for the Asciidoctor `:stem: latexmath`. For details, see
 the [Asciidoctor user manual](https://asciidoctor.org/docs/user-manual/#activating-stem-support).
 
 ### Special GitLab references
@@ -447,7 +445,7 @@ recognized and formatted with text `#123`.
 
 In addition to this, links to some objects are also recognized and formatted. Some examples of these are:
 
-- Comments on issues: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234#note_101075757"`, which are rendered as `#1234 (note1)`
+- Comments on issues: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234#note_101075757"`, which are rendered as `#1234 (comment 101075757)`
 - The issues designs tab: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234/designs"`, which are rendered as `#1234 (designs)`.
 - Links to individual designs: `"https://gitlab.com/gitlab-org/gitlab/-/issues/1234/designs/layout.png"`, which are rendered as `#1234[layout.png]`.
 
@@ -608,9 +606,9 @@ Quote break.
 
 #### Multiline blockquote
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#multiline-blockquote).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#multiline-blockquote).
 
-GFM extends the standard Markdown standard by also supporting multi-line blockquotes
+GFM extends the standard Markdown by also supporting multi-line blockquotes
 fenced by `>>>`:
 
 ```markdown
@@ -689,7 +687,7 @@ Tildes are OK too.
 
 #### Colored code and syntax highlighting
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#colored-code-and-syntax-highlighting).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#colored-code-and-syntax-highlighting).
 
 GitLab uses the [Rouge Ruby library](http://rouge.jneen.net/) for more colorful syntax
 highlighting in code blocks. For a list of supported languages visit the
@@ -782,7 +780,7 @@ Strikethrough is not part of the core Markdown standard, but is part of GFM.
 
 #### Multiple underscores in words and mid-word emphasis
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#multiple-underscores-in-words).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#multiple-underscores-in-words).
 
 It's not usually useful to italicize just _part_ of a word, especially when you're
 dealing with code and names that often appear with multiple underscores. As a result,
@@ -974,7 +972,7 @@ Do not change to a reference style link.
 
 #### Videos
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#videos).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#videos).
 
 Image tags that link to files with a video extension are automatically converted to
 a video player. The valid video extensions are `.mp4`, `.m4v`, `.mov`, `.webm`, and `.ogv`:
@@ -991,7 +989,7 @@ Here's a sample video:
 
 #### Audio
 
-> If this is not rendered correctly, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#audio).
+If this section is not rendered correctly, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#audio).
 
 Similar to videos, link tags for files with an audio extension are automatically converted to
 an audio player. The valid audio extensions are `.mp3`, `.oga`, `.ogg`, `.spx`, and `.wav`:
@@ -1008,7 +1006,7 @@ Here's a sample audio clip:
 
 ### Inline HTML
 
-> To see the Markdown rendered within HTML in the second example, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#inline-html).
+To see the Markdown rendered within HTML in the second example, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#inline-html).
 
 You can also use raw HTML in your Markdown, and it usually works pretty well.
 
@@ -1072,7 +1070,7 @@ Markdown is fine in GitLab.
 
 #### Details and summary
 
-> To see the Markdown rendered within HTML in the second example, [view it in GitLab itself](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#details-and-summary).
+To see the Markdown rendered within HTML in the second example, [view it in GitLab](https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/markdown.md#details-and-summary).
 
 Content can be collapsed using HTML's [`<details>`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/details)
 and [`<summary>`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/summary)
@@ -1106,7 +1104,7 @@ These details <em>remain</em> <strong>hidden</strong> until expanded.
 
 Markdown inside these tags is supported as well.
 
-NOTE: **Note:**
+TIP: **Tip:**
 If your Markdown isn't rendering correctly, try adding
 `{::options parse_block_html="true" /}` to the top of the page, and add
 `markdown="span"` to the opening summary tag like this: `<summary markdown="span">`.
@@ -1475,5 +1473,5 @@ entry and paste the spreadsheet:
 - This document leveraged heavily from the [Markdown-Cheatsheet](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet).
 - The original [Markdown Syntax Guide](https://daringfireball.net/projects/markdown/syntax)
   at Daring Fireball is an excellent resource for a detailed explanation of standard Markdown.
-- The detailed specification for CommonMark can be found in the [CommonMark Spec](https://spec.commonmark.org/current/)
-- The [CommonMark Dingus](http://try.commonmark.org) is a handy tool for testing CommonMark syntax.
+- You can find the detailed specification for CommonMark in the [CommonMark Spec](https://spec.commonmark.org/current/).
+- The [CommonMark Dingus](https://spec.commonmark.org/dingus/) is a handy tool for testing CommonMark syntax.