Merge branch '323310-add-release-13-12-to-upgrade-path-docs' into 'master'

Docs: Add v13.12 to upgrage path

See merge request gitlab-org/gitlab!63605

doc/update/index.md

@@ -194,7 +194,7 @@ Find where your version sits in the upgrade path below, and upgrade GitLab
 accordingly, while also consulting the
 [version-specific upgrade instructions](#version-specific-upgrading-instructions):
 
-`8.11.Z` -> `8.12.0` -> `8.17.7` -> `9.5.10` -> `10.8.7` -> `11.11.8` -> `12.0.12` -> `12.1.17` -> `12.10.14` -> `13.0.14` -> `13.1.11`  -> [latest `13.Y.Z`](https://about.gitlab.com/releases/categories/releases/)
+`8.11.Z` -> `8.12.0` -> `8.17.7` -> `9.5.10` -> `10.8.7` -> `11.11.8` -> `12.0.12` -> `12.1.17` -> `12.10.14` -> `13.0.14` -> `13.1.11` -> [latest `13.12.Z`](https://about.gitlab.com/releases/categories/releases/) -> [latest `14.0.Z`](https://about.gitlab.com/releases/categories/releases/)
 
 The following table, while not exhaustive, shows some examples of the supported
 upgrade paths.