Reduce barrier of entry for translation

**Your Godot version:**
n/a
**Issue description:**
I found a mistake in a page translation and wanted to fix it. After clicking multiple links I finally got to weblate which was hella confusing and I gave up (I did post it in the relevant channel at chat.godotengine.org).
If you're on an english page you get this handy "Edit on GitHub" button:
An equivalent of that for the translated pages would be great, instead of "View page source"
**URL to the documentation page (if already existing):**
n/a