Changelog Description

resolve #266
This PR ports ynput/ayon-core#1441 fixes for applications addon.

Add a CI action to trigger MK Docs deployment on creating new tags.
when testing the CI action manually (trigger from Action tab manually on GH), it will generate a dummy-build version that will be deleted as soon as a tag is created.

Additional Notes

This PR add some cosmetics:

1. update light and dark mode icons.
2. move requirements file to root location of the repo to avoid moving it along with the docs build.

Testing notes:

1. go to https://docs.ayon.dev/ayon-launcher/latest/ you should find light/dark icons are updated and the latest is pointing to test-build.
   since the workflow doesn't exist in main branch yet, I had to add on push temporarily in c5ab269 to run the action and revert it in a later commit.