Create contributing guide for keink project

[anshgoyalevil]

Currently, the keink project doesn't contain a contributing guide.

Expected Behaviour:

There should be contributing guide as per CNCF templates which can be followed to start local development of the project.

It can include sections like Signing Off Commits, Running in Local Dev Environment, etc.

[anshgoyalevil]

@fisherxu

I would like to work on this issue and create a contribution guide.

[vishalrajofficial]

I'm interested and confident enough to contribute to this issue for creating contributing guide as per provided norms.