Requirements:
- You need a machine that is running Linux or macOS. 
- You need to have these tools installed: 
- Your - PATHenvironment variable must include the required build tools, such as the- Gobinary and- python.
- You need to know how to create a pull request to a GitHub repository. This involves creating your own fork of the repository. For more information, see Work from a local clone. 
Last modified July 17, 2020 at 12:07 PM PST: Tidy up: fix bad links in contribution guide (139da7d731)