Update libmpdec-related instructions - #1907

Process completed with exit code 2.

redirect https://docs.github.com/en/get-started/getting-started-with-git/set-up-git - permanently to https://docs.github.com/en/get-started/git-basics/set-up-git

redirect https://discuss.python.org/t/103356/2 - permanently to https://discuss.python.org/t/windows-code-signing-certificates-for-python-3-12-8-3-13-1-revoked/103356/2

redirect https://discuss.python.org/faq - with Found to https://discuss.python.org/guidelines

redirect https://discuss.python.org/c/documentation/translations/ - permanently to https://discuss.python.org/c/documentation/translations/39

redirect https://discuss.python.org/c/core-dev/c-api/ - permanently to https://discuss.python.org/c/core-dev/c-api/30

redirect https://discord.gg/h3qDwgyzga - permanently to https://discord.com/invite/h3qDwgyzga

redirect https://discord.gg/JNWjefK2yG - permanently to https://discord.com/invite/JNWjefK2yG

redirect https://app.transifex.com/sphinx-doc/ - with Found to https://app.transifex.com/sphinx-doc/signin/?next=/sphinx-doc/

redirect http://cnri.reston.va.us/ - permanently to https://cnri.reston.va.us/

rst:role reference target not found: py:func [ref.role]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]

Git clone too shallow [git.too_shallow]