docs: Add a CONTRIBUTING.md file

CONTRIBUTING.md

@@ -0,0 +1,22 @@
+# Contributing
+
+Issues, bug fixes and documentation for existing features are always
+welcome.
+
+## Proposing Features
+
+The focus on this project is on providing a convenient way to access
+the schema for code generators targetting different langauges.
+Features that aren't relevant for this use case are less likely to
+be merged. When in doubt, open an issue first to propose the issue
+so that we can confirm that we are interested in a pull request to
+implement it.
+
+## How To Contribute
+
+1. Fork the [repository in github](https://github.com/Shopify/graphql_schema)
+2. Create your feature branch (`git checkout -b fix-feature`)
+3. Commit your changes (`git commit -am 'fix: Summarize change'`)
+3. Make sure all tests pass (`bundle exec rake`)
+4. Push to the branch (`git push origin fix-feature`)
+5. [Create new pull request](https://github.com/Shopify/graphql_schema/pulls)

README.md

@@ -42,7 +42,7 @@ To install this gem onto your local machine, run `bundle exec rake install`. To
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/Shopify/graphql_schema.
+See our [contributing guidelines](CONTRIBUTING.md) for more information.
 
 ## License