docs: fix missing API entries (#3111)

following up on
https://discord.com/channels/859816885297741824/1162726738774720574/1211715924613275681

several things here:
- `docs/api/.*json` were out-of-date — seems like fetch-api-source
should run automatically? shouldn't `build-api` also override this
directory? in particular, tldraw.api.json still had a ton of references
to the old @tldraw/tldraw package
- the main problem was that `generateApiContent` was failing silently.
we were relying on Promises and this broke silently because we never
handled exceptions. i got rid of the Promise as it was unnecessary and
made the exceptions bubble up
- two things were broken in the docs and those are fixed, so now the
missing entries will resurface

### Change Type

- [x] `documentation` — Changes to the documentation only[^2]

---------

Co-authored-by: Steve Ruiz <steveruizok@gmail.com>

apps/docs/scripts/functions/fetchReleases.ts

@@ -3,7 +3,7 @@ import { Octokit } from 'octokit'
 import path from 'path'
 
 const octokit = new Octokit({
-	auth: process.env.GITHUB_ACCESS_TOKEN,
+	auth: process.env.ACCESS_TOKEN,
 })
 
 const { log: nicelog } = console