chore(docs): switch gitRevision to main and update source links

[barhanc]

Description

1. Switched "gitRevision" from "rne-rewrite" to "main" (and removed the temporary _todo).
2. Docs markdown guides: Updated all GitHub source code links (/blob/rne-rewrite/... ➔ /blob/main/...) across all extension guides.

Introduces a breaking change?

• Yes
• No

Type of change

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Documentation update (improves or adds clarity to existing documentation)
• Other (chores, tests, code style improvements etc.)

Tested on

• iOS
• Android

Testing instructions

N/A

Screenshots

Related issues

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes