Update README and examples copy in the docs (#2594)

This PR should make the examples page copy clearer:

1. Moved the examples app copy above the framework specific and yjs
copy, as it's more likely to be what the user is looking for.
2. Moved the codesandbox below the copy, user no longer needs to scroll
to see most of the text.
3. Gives more hints about what can be found in the examples app and also
highlights that running it locally is the better experience.
4. Added some clarification on the relationship between the
framework-specific examples/yjs example and the examples app
5. Updates the tldraw repo README accordingly.
6. Removes (development) from the Basic example.

Next steps:
- The codesandbox
   - quite noisy, would be good to hide the navigation
   - doesn't reliably show the code and implementation at the same time
   - Should stack vertically on small screens

### Change Type

- [ ] `patch` — Bug fix
- [ ] `minor` — New feature
- [ ] `major` — Breaking change
- [ ] `dependencies` — Changes to package dependencies[^1]
- [x] `documentation` — Changes to the documentation only[^2]
- [ ] `tests` — Changes to any test code only[^2]
- [ ] `internal` — Any other changes that don't affect the published
package[^2]
- [ ] I don't know

[^1]: publishes a `patch` release, for devDependencies use `internal`
[^2]: will not publish a new version

### Release Notes

- Update examples copy and tldraw README

README.md

@@ -14,6 +14,8 @@ Welcome to the public monorepo for [tldraw](https://github.com/tldraw/tldraw). t
 
 ## Local development
 
+The local development server will run our examples app. The basic example will show any changes you've made to the codebase.
+
 To run the local development server, first clone this repo.
 
 Install dependencies:

apps/examples/src/examples/develop/README.md

@@ -1,5 +1,5 @@
 ---
-title: Basic (development)
+title: Basic
 component: ./BasicExample.tsx
 order: 1
 ---