[3] Add version support to our public docs

[Pavan-Gunda]

We need to add version support to our public docs. After the investigation, we decided on some action points.

Action points:

1. Announce public docs are in maintenance mode.
2. Disable CI/CD pipeline
3. Create branches: release-v0.20, release-v0.21 and release-v0.22. (each versions points to their respective branch)
4. Locally write CI/CD deploy script, which takes GITHUB_REF_NAME and does the right mike command.
5. Update CI/CD GitHub Action and make things work.

Acceptance criteria:

https://user-images.githubusercontent.com/55189254/173024879-79208cfc-425c-4cbc-9c81-6c1cdd3d6b02.mp4

https://user-images.githubusercontent.com/55189254/173024891-bbd29013-adaf-481e-82d8-5eefc93cd0e8.mp4

Definition of done:

The version support should be working and all the URLs within the public docs, either intact or modified, should work with the new setup.

Document about mike in the contributor guide.