docs: Simplify sphinx build and table of contents on webpage

[rmccorm4]

Overview:

• Revamp table of contents on left hand side to be leaner
• Removes some unused things from Triton repo in conf.py
• Removes some dead/outdated symlinks
• Removes outdated dynamo deploy quickstart - there were 3 (README, dynamo_cloud.md, quickstart.md) - now there are 2 - to be improved by @athreesh to reduce to 1
• Updates versions in docs from 0.4.0 to 0.4.1 in prep for release
• Remove load based planner from ToC per Anish feedback
• Remove model caching with fluid from ToC per Anish feedback

Disclaimers

• This PR is NOT trying to have a 1:1 mapping between docs page and list of markdown files on GitHub. It's trying to give a more streamlined/curated step through of docs for newer users for now.
• Not all relative paths on certain nested markdown files will go anywhere when viewed on html page. They shouldn't be broken/404 links, but may be no-ops. This is a known issue with the docs building process, and until we improve the process itself, some links in one of either GitHub or docs.nvidia.com may not work. Until we smoothly support both, for now GitHub links working is prioritized as the types of links that break are primarily relative paths to scripts for developers following guides deep in the codebase folders. Relative paths/links viewed in GitHub should all work for now, but may not on docs.nvidia.com until improved.

Details

Before:

After (v2):

Backup

After (v1)