[CLOSED] Move website

[naskio]

What type of PR is this?

Improve website build and deployment process

What this PR does / why we need it:

• Currently, we are using "Deploy from a branch" as source for building and deploying the website to GitHub Pages.
• There's also the workflow "Deploy GH Pages" at .github/workflows/pages.yml which is responsible fo copying files from master to gh-pages branch.

Which issue(s) this PR fixes:

Fixes #3715

This PR includes the following:

• Moving the website/ source code from the gh-pages branch to master under website/ folder.
• Removing useless website/CNAME file (This file won't work with "GitHub Actions" as source, refer to the docs for more details)
• Removing unused website/.circleci/ folder (CircleCI is not being used as you can see here)
• Removing unneeded website/.mergify.yml file (Not needed because we won't use a branch anymore)
• Renaming website/README.txt to website/README.md and convert to Markdown format (this would allow GitHub to display a formatted page)
• Renaming docs/docs-readme.md to docs/README.md (This would allow GitHub to display a formatted page)
• Update Jekyll _config.yml to exclude README.md, copy.sh, Gemfile, Gemfile.lock from output (For example, we won't have this file anymore https://armadaproject.io/Gemfile)

Special notes for your reviewer:

Once this PR is merged, we would also need to:

• Set "Source" to "GitHub Actions" in "Settings > Pages > Build and deployment > Source".
• Set "Custom domain" to armadaproject.io in "Settings > Pages > Build and deployment > Custom domain".
• Get rid of the gh-pages branch (Optional).

[naskio]

Replaced by #3850