Update Documentation theme from sphinx_rtd_theme to sphinx_book_theme

[oliverholworthy]

Update Documentation theme from sphinx_rtd_theme to sphinx_book_theme

[github-actions]

Documentation preview

https://nvidia-merlin.github.io/Merlin/review/pr-1046

[mikemckiernan]

Hi folks, just passing by while trying to view another issue...if you are tempted to change the appearance of the docs, consider using repo_docs:

http://omniverse-docs.s3-website-us-east-1.amazonaws.com/repo_docs/0.37.0/index.html

It's about as close to a "standard" as we have. (As of now, it does not, however, offer a three-column layout like the books theme.)

[oliverholworthy]

Hi folks, just passing by while trying to view another issue...if you are tempted to change the appearance of the docs, consider using repo_docs:

http://omniverse-docs.s3-website-us-east-1.amazonaws.com/repo_docs/0.37.0/index.html

It's about as close to a "standard" as we have. (As of now, it does not, however, offer a three-column layout like the books theme.)

Thanks @mikemckiernan . I copied some of the CSS from the Omniverse docs to get closer to that theme in style. We can do some follow-up work to investigate repo_docs. This PR at least get's us a step closer in appearance (similar to the Triton Docs and NeMo docs)