* [vcpkg docs] Change how documenting port functions works
Instead of using `##`, use comment blocks for documentation.
Also, add some minor docs and change RST -> MD
so we actually get docs generated.
* add CI stuff
* regenerate docs
* fix vcpkg_find_acquire_program to not use _execute_process
If you changed VCPKG_TARGET_ARCHITECTURE to use x86_64, the prettify command failed to parse things properly. This was found during the changes made for #12657 and was completed by @strega-nil (thanks!).