Update README.md

Author: cheny0y0

docs/contribute/README.md

@@ -2,7 +2,10 @@
 1. Go to <https://scratch.mit.edu/download> to download, install and launch Scratch 3.0.
 2. Create some custom blocks with “default cat” or a blank sprite.
 3. Save.
+
 # Work with GitHub
 4. Update your files to [144881-Studios/physics-engine/source-blocks/](https://github.com/144881-Studios/physics-engine/tree/master/source-blocks/) and open a pull request.
 5. Wait for audit.
 6. Well done!
+-----
+[Contribute to us](https://144881-studios.github.io/physics-engine/contribute) [Email to us](mailto:cyy144881@icloud.com?subject=Scratch%203.0%20physics%20engine)