Update CONTRIBUTING.md (#159)

CONTRIBUTING.md

@@ -10,7 +10,7 @@ If you are reporting a bug, please help speed up problem diagnosis by providing
 
 ## Contributing code
 We actively welcome your pull requests. You can find instructions on building the project in [README.md](https://github.com/canopas/khelo).
-1. Fork the repo and create your branch from `master`.
+1. Fork the repo and create your branch from `main`.
 2. If you've added code that should be tested, add tests.
 3. Make sure your code lints.
 
@@ -29,4 +29,4 @@ Labels on issues are managed by contributors, you don't have to worry about them
 * **non-library**: issue is not in the core library code, but rather in documentation, samples, build process, releases
 
 ## License
-By contributing to Khelo, you agree that your contributions will be licensed under its Apache License, Version 2.0. See LICENSE file for details.
+By contributing to Khelo, you agree that your contributions will be licensed under its Apache License, Version 2.0. See LICENSE file for details.