PG-2275 - Repository 404 errors and removed versions (17)

This PR adds a new file in the troubleshooting section explaining why some versions are no longer available to download.

Author: Andriciuc

docs/remove-repo-ver.md

@@ -0,0 +1,31 @@
+# Removed repository versions
+
+## Overview
+
+Some Percona Distribution for PostgreSQL repository versions are no longer available and may return a `404 Not Found` error when accessed. The affected versions are:
+
+- ppg-14.19
+- ppg-15.14
+- ppg-16.10
+- ppg-17.6
+
+## Reason for removal
+
+These versions were part of a release that included known issues affecting stability and reliability (also referred to internally as the "assertion release").
+
+To prevent unintended usage, these repositories were removed from distribution.
+
+## What should you do instead?
+
+Use the latest available minor version for your PostgreSQL major version.
+
+Example:
+
+- Instead of `ppg-16.10`, use the latest `ppg-16.x`
+
+See [installation guide]
+
+## Additional context
+
+For more details, see the relevant release notes:
+- [link to release notes]

mkdocs.yml

@@ -71,7 +71,9 @@ nav:
       - minor-upgrade.md
       - migration.md
   - FAQ: faq.md  
-  - Troubleshooting guide: troubleshooting.md
+  - Troubleshooting guide: 
+      - "Overview": troubleshooting.md
+      - "Repository 404 errors and removed versions": remove-repo-ver.md
   - Uninstall: uninstalling.md
   - Release notes:
       - "Release notes index": release-notes/release-notes.md