give the docs some ✨ polish ✨

[OwenPriceSkelly]

Some gripes about the docs:

• Clean up home page ("Docs are a WIP" get out of here)
  • 1-sentence elevator pitch and TOC is good
  • what's the motivation to use this/read the rest of the docs?
• Explain Entrypoint concept before Garden concept
• Should link to the website
  • should link to real examples on the website
• Fix API autodocs for metadata classes
  • Include usage example for linking Dataset/Paper/Models
• see if we can drop the garden-ai prefix on the CLI autodocs TOC
• the "User guide" > "Introduction" page is almost identical to the home page
• Flesh out FAQs page