[DOCS] Automatically audit and flag broken URLs in codebase/docs

[ScriptAutomate]

Description

Automatically audit and flag broken URLs in codebase/docs

Suggested Fix

Use GitHub Actions to verify that links across the codebase/docs are not broken.

Using Sphinx's built-in linkcheck doesn't include validating links across the rest of the project, such as within any *.md files, or configuration files.

Type of documentation

• Salt documentation
• Salt modules