docs: coalesce contributing guildelines

CONTRIBUTING.md

@@ -4,6 +4,20 @@ IPFS as a project and community follows the [standard IPFS Community contributin
 
 We appreciate your time and attention for going over these. Please open an issue on [ipfs/community](https://github.com/ipfs/community) if you have any question.
 
+## Contributing Code
+
+If you plan to contribute code, make sure to install the [pre-commit](https://github.com/pre-commit/pre-commit) tool, which manages our pre-commit hooks for things like linters, go fmt, go vet, etc.
+
+We provide a `Makefile` rule to facilitate the setup:
+
+```sh
+$ make pre-commit
+```
+
+[![](https://cdn.rawgit.com/jbenet/contribute-ipfs-gif/master/img/contribute.gif)](https://github.com/ipfs/community/blob/master/CONTRIBUTING.md)
+
+## Communication channels
+
 **In addition**, please read through the [HOW WE WORK TOGETHER](https://github.com/ipfs/testground/blob/master/docs/HOW_WE_WORK.md) document to learn how the team operates and expects information to be propagated.
 
 Thank you ❤️