create CODEOWNERS file

CONTRIBUTING.md

@@ -2,14 +2,14 @@
 
 We welcome contributions from anyone who is willing to create a new PR on farming module, make sure that you read and comply with this document. See the [open issues](https://github.com/tendermint/farming/issues) that we need help with. Feel free to inform us if you are willing to work on any issue. Note that the `master` branch contains the latest development version. 
 
-We follow standard github best practices: 
+We follow standard GitHub best practices: 
 
 - Fork the repository
 - Make sure your `branch` is from the tip of `master` branch
 - Make some commits to resolve an issue
 - Submit a pull request to `master`
 
-Rule of thumb:
+General guidance:
 
 - Make sure you run tests by running `make test-all` locally to see there is any issue
 - Review all the checks on your PR and review code coverage report