Switch to recommending direct github actions deploy to github pages over using the gh-pages branch

[amithkk]

GitHub actions now natively supports the capability to publish directly to github pages without needing to commit code to the gh-pages branch, which removes the need to commit generated source code.

This is done with the https://github.com/marketplace/actions/deploy-to-github-pages action. However the documentation still recommends use of the gh-pages branch.