Add note about GitLab Pages and redirects

Issue: https://gitlab.com/gitlab-org/gitlab/-/issues/342781

doc/user/project/pages/redirects.md

@@ -163,6 +163,12 @@ Splats also match empty strings, so the previous rule redirects
 
 ### Rewrite all requests to a root `index.html`
 
+NOTE:
+If you are using [GitLab Pages integration with Let’s Encrypt](custom_domains_ssl_tls_certification/lets_encrypt_integration.md),
+you must enable it before adding this rule. Otherwise, the redirection breaks the Let's Encrypt
+integration. For more details, see
+[GitLab Pages issue 649](https://gitlab.com/gitlab-org/gitlab-pages/-/issues/649).
+
 Single page applications (SPAs) often perform their own routing using
 client-side routes. For these applications, it's important that _all_ requests
 are rewritten to the root `index.html` so that the routing logic can be handled
@@ -180,7 +186,7 @@ rule like:
 Use placeholders in rules to match portions of the requested URL and use these
 matches when rewriting or redirecting to a new URL.
 
-A placehold is formatted as a `:` character followed by a string of letters
+A placeholder is formatted as a `:` character followed by a string of letters
 (`[a-zA-Z]+`) in both the `from` and `to` paths:
 
 ```plaintext