docs: add star history and contributor list to README. (#2914)

Describe what your pull request does. If appropriate, add GIFs or images
showing the before and after.

### 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

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

### Test Plan

No need to test

### Release Notes

add star history and contributor list to README.

<img width="854" alt="image"
src="https://github.com/tldraw/tldraw/assets/42437658/d0c73289-9fb1-4dc0-882a-0593ebc13895">


- Increases project transparency: This can help other developers
understand the popularity and activity level of the project.

- Recognizes contributors: Listing contributors can recognize those who
have contributed to the project, which may also motivate more people to
participate in the project.

- Provides more information: The star history chart and contributor list
provide more information for potential users or contributors, helping
them make decisions about whether to use or participate in the project.

- Enhances the project's professionalism: A detailed README file can
enhance the professionalism of the

README.md

@@ -52,6 +52,17 @@ Have questions, comments or feedback? [Join our discord](https://discord.gg/rhsy
 
 Please see our [contributing guide](https://github.com/tldraw/tldraw/blob/main/CONTRIBUTING.md). Found a bug? Please [submit an issue](https://github.com/tldraw/tldraw/issues/new).
 
+## Contributors
+<a href="https://github.com/tldraw/tldraw/graphs/contributors">
+  <img src="https://contrib.rocks/image?repo=tldraw/tldraw" width="100%"/>
+</a>
+
+## Star History
+
+<a href="https://star-history.com/#tldraw/tldraw">
+  <img src="https://api.star-history.com/svg?repos=tldraw/tldraw&type=Date" alt="Star History Chart" width="100%" />
+</a>
+
 ## Contact
 
 Find us on Twitter at [@tldraw](https://twitter.com/tldraw) or email [sales@tldraw.com](mailto://sales@tldraw.com). You can also [join our discord](https://discord.gg/rhsyWMUJxd) for quick help and support.