docs: Add Contributing section

Author: medikoo

README.md

@@ -4,6 +4,16 @@
 
 This plugin enables support for [Google Cloud Functions](https://cloud.google.com/functions/) within the [Serverless Framework](https://github.com/serverless/serverless).
 
+## Contributing
+
+We are always looking to promote good contributors to be maintainers and provide them a front-row seat to serverless innovation.
+
+If you would like to be a maintainer of this plugin, please get started with making code contributions and engaging with open issues/PRs. Also, please reach out to one of the active [Serverless organization](https://github.com/serverless) members to express your interest.
+
+We'd love to collaborate closely with amazing developers as we drive the development of this open technology into the future.
+
+Welcome, and thanks in advance for your help!
+
 ## Documentation
 
 The documentation can be found [here](https://serverless.com/framework/docs/providers/google).