Backport Docs code links (#7740)

* Docs code links (#7342)

* Update docs

- Add note about permission denied error

* Add macro for generating link to github code

* Implement similar feature for source directory links

* Adds helper function for link checking

* Allow for specification of "raw" file links

* Remove debug statement

* Generate list of available invoke tasks

(cherry picked from commit 797a0c10df)

* auto-detect current branch and use that for links

* remove debug logging

* style fix

* spell fix

---------

Co-authored-by: Oliver <oliver.henry.walters@gmail.com>

docs/.gitignore

@@ -13,6 +13,10 @@ site/
 # Generated API schema files
 docs/api/schema/*.yml
 
+# Temporary cache files
+url_cache.txt
+invoke-commands.txt
+
 # Temp files
 releases.json
 versions.json