Update extension extraction docs (#24079)

- Fixed a regex for finding tags.
- Templatize the instructions with `$LANGNAME` to prevent manual errors
from failing to edit commands (this bit me)
- Ran formatting through Prettier
5315d38cf4Peter Tripp committed on 2/7/2025, 12:01:32 AM· committed by GitHubparent337b9e6
2 files changedLine totals unavailable