fix(docs): add noindex option & canonical url

[RhysSullivan]

Fixes https://x.com/t3dotgg/status/1766445250527351012?s=20

Noindex:

While there are ways to auto detect this, i.e off of the Vercel env variable. But given that noindex is more of a destructive action imo it should be manually set.

In the dev & preview branches, set NEXT_PUBLIC_DISABLE_INDEXING to true in the env vars & validate

Canonical Url:

Uses https://docs.uploadthing.com as the default, adds on the path name. Should also help with deduplication & and forks that don't have the environment variable set.

[changeset-bot[bot]]

⚠️ No Changeset found

Latest commit: cc8f5aa4bbf972cc65725135514c40cf0ce18ca0

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
docs-uploadthing	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Mar 10, 2024 10:07am

[markflorkowski]