Split troubleshooting docs review apps in own section

doc/development/documentation/index.md

@@ -451,16 +451,6 @@ preview the changes. The docs URL can be found in two places:
 - In the output of the `review-docs-deploy*` job, which also includes the
   triggered pipeline so that you can investigate whether something went wrong
 
-In case the Review App URL returns 404, follow these steps to debug:
-
-1. **Did you follow the URL from the merge request widget?** If yes, then check if
-   the link is the same as the one in the job output.
-1. **Did you follow the URL from the job output?** If yes, then it means that
-   either the site is not yet deployed or something went wrong with the remote
-   pipeline. Give it a few minutes and it should appear online, otherwise you
-   can check the status of the remote pipeline from the link in the job output.
-   If the pipeline failed or got stuck, drop a line in the `#docs` chat channel.
-
 TIP: **Tip:**
 Someone that has no merge rights to the CE/EE projects (think of forks from
 contributors) will not be able to run the manual job. In that case, you can
@@ -472,6 +462,18 @@ working on. If you don't, the remote docs branch won't be removed either,
 and the server where the Review Apps are hosted will eventually be out of
 disk space.
 
+### Troubleshooting review apps
+
+In case the review app URL returns 404, follow these steps to debug:
+
+1. **Did you follow the URL from the merge request widget?** If yes, then check if
+   the link is the same as the one in the job output.
+1. **Did you follow the URL from the job output?** If yes, then it means that
+   either the site is not yet deployed or something went wrong with the remote
+   pipeline. Give it a few minutes and it should appear online, otherwise you
+   can check the status of the remote pipeline from the link in the job output.
+   If the pipeline failed or got stuck, drop a line in the `#docs` chat channel.
+
 ### Technical aspects
 
 If you want to know the hot details, here's what's really happening: