Rename `@tldraw/tldraw` to just `tldraw`! `@tldraw/tldraw` still exists
as an alias to `tldraw` for folks who are still using that.
### Test Plan
- [x] Unit Tests
- [ ] End to end tests
### Release Notes
- The `@tldraw/tldraw` package has been renamed to `tldraw`. You can
keep using the old version if you want though!
