Add a "Best Practices" section to CONTRIBUTING.md
Add a "Best Practices" section to CONTRIBUTING.md

pmkc/dataproc-initialization-actions,dennishuo/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions,lukeFalsina/dataproc-initialization-actions,dennishuo/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions,pmkc/dataproc-initialization-actions,GoogleCloudDataproc/initialization-actions,lukeFalsina/dataproc-initialization-actions