Feature request: A way to convert Jenkin YML into SAM yml

### I am a full stack Software Engineer with Node/AWS stack at one of the companies, in my company, we have a repo with the tone of the lambda functions, which are triggering from API Gateway, SNS, SQS, etc. After I joined the team, I realized making small changes and testing is very time-consuming because I needed to deploy that small changes to the AWS Console using Jenkin Pipeline (.yml) file. So, I have come across this `sam-cli-tool`, which is mind-blowing, and it provides a way to invoke and test, lambdas locally.

Problem: instead of initiating a new SAM project, I wish I could use `sam` on the existing repo. I wish I could convert my Jenkin pipeline YML file to SAM YML and start using it. I don't see any way which we can do that in the command line tool.