Here are the key points from the document in 3 sentences or less:
Contributing to open source projects like Grails can be done in many ways such as submitting pull requests and issues on GitHub, commenting on issues in JIRA, improving documentation, and contributing code changes to the core Grails framework by cloning the GitHub repository and submitting pull requests. The document provides guidance on getting started with contributions through various components of the Grails project and how contributing can help both the project and yourself as a developer through an improved experience and recognition within the community. Contributing is encouraged for anyone interested in helping to further develop Grails.