[DOC] Automate publishing documentation with github workflow

[karthikeyann]

Automate the publishing of documentation to keep it upto date.

https://github.com/NVIDIA/cuCollections/pull/177#issuecomment-1160655675 main branch is not updated in long time (July 16, 2020) dev branch is updated frequently. There are no releases or tags. So decide when to publish the documentation and which branch.

Describe the solution you'd like Similar to thrust, add a GitHub workflow to generate and publish documentation to gh-pages https://github.com/NVIDIA/thrust/blob/main/.github/workflows/deploy-documentation-github-pages.yml