Docs: Bring HTML Style Guide in line with docs standards

doc/development/new_fe_guide/style/html.md

@@ -2,11 +2,11 @@
 
 ## Buttons
 
-<a name="button-type"></a><a name="1.1"></a>
+### Button type
 
-- [1.1](#button-type) **Use button type** Button tags requires a `type` attribute according to the [W3C HTML specification][button-type-spec].
+Button tags requires a `type` attribute according to the [W3C HTML specification](https://www.w3.org/TR/2011/WD-html5-20110525/the-button-element.html#dom-button-type).
 
-```
+```html
 // bad
 <button></button>
 
@@ -14,11 +14,11 @@
 <button type="button"></button>
 ```
 
-<a name="button-role"></a><a name="1.2"></a>
+### Button role
 
-- [1.2](#button-role) **Use button role for non buttons** If an HTML element has an onClick handler but is not a button, it should have `role="button"`. This is more [accessible][button-role-accessible].
+If an HTML element has an `onClick` handler but is not a button, it should have `role="button"`. This is [more accessible](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_button_role).
 
-```
+```html
 // bad
 <div onClick="doSomething"></div>
 
@@ -28,11 +28,11 @@
 
 ## Links
 
-<a name="blank-links"></a><a name="2.1"></a>
+### Blank target
 
-- [2.1](#blank-links) **Use rel for target blank** Use `rel="noopener noreferrer"` whenever your links open in a new window i.e. `target="_blank"`. This prevents [the following][jitbit-target-blank] security vulnerability documented by JitBit
+Use `rel="noopener noreferrer"` whenever your links open in a new window, i.e. `target="_blank"`. This prevents a security vulnerability [documented by JitBit](https://www.jitbit.com/alexblog/256-targetblank---the-most-underestimated-vulnerability-ever/).
 
-```
+```html
 // bad
 <a href="url" target="_blank"></a>
 
@@ -40,18 +40,14 @@
 <a href="url" target="_blank" rel="noopener noreferrer"></a>
 ```
 
-<a name="fake-links"></a><a name="2.2"></a>
+### Fake links
 
-- [2.2](#fake-links) **Do not use fake links** Use a button tag if a link only invokes JavaScript click event handlers. This is more semantic.
+**Do not use fake links.** Use a button tag if a link only invokes JavaScript click event handlers, which is more semantic.
 
-```
+```html
 // bad
 <a class="js-do-something" href="#"></a>
 
 // good
 <button class="js-do-something" type="button"></button>
 ```
-
-[button-type-spec]: https://www.w3.org/TR/2011/WD-html5-20110525/the-button-element.html#dom-button-type
-[button-role-accessible]: https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_button_role
-[jitbit-target-blank]: https://www.jitbit.com/alexblog/256-targetblank---the-most-underestimated-vulnerability-ever/