Missing contribution guidelines for alpha stage APIs

[artur-ciocanu]

Expected Behavior

The CONTRIBUTING.md file should contain enough details about how should we contribute implementations for alpha stage APIs like:

• where should we add the APIs to which interface
• how should we prefix the alpha API methods, like Alpha1
• which version should we use like 1.x.x vs 0.x.x for alpha stage modules

Actual Behavior

Currently there are no instructions in the CONTRIBUTING.md file.

Steps to Reproduce the Problem

Please check the current CONTRIBUTING.md file.

Release Note

RELEASE NOTE:

[artur-ciocanu]

@cicoyle and @salaboy could you please let me know your thoughts.

[siri-varma]

I think this is a great idea. But do you think we could further offload it to contributors by adding some automation, like Checkstyle? For example, alpha APIs usually have 'alpha' in their method names. We could create a rule to check if a method name from the Dapr import contains 'alpha' and ensure the calling method also has 'alpha' in its name.

I understand it is easier said than done. But wanted to know everyone thoughts as well.

[cicoyle]

Our Contributing.md file mostly aligns with dapr/dapr's. I would be happy to see it expanded on.