Create a chapter for contributing for delivering code

[Joe-Winchester]

Is your request for enhancement related to a problem? Please describe.

the Zowe docs don't have a section for folks wanting to contribute code to Zowe, or for committers to find out how to run builds and tests

Describe the solution you'd like

https://docs.zowe.org/stable/contribute
has sections for adding docs, for some coding standards, but nothing for how to write code and submit pull requests to Zowe or how to run builds or tests.