Guidelines for new developer contribution

Versions (relevant - OpenSearch/Dashboard/Server OS/Browser):

Describe the issue:
For any new developer, it’s difficult to understand the guidelines for contribution.

=> I don’t see any guidelines about the development branch to start.

=> Every time yarn start:docker takes almost more than 20-25mins to get up. So is there any
specific system configuration for this project to run?


Relevant Logs or Screenshots: