Implement GitHub action for Score

[sujaya-sys]

Implement an open-source GitHub action that adds a Score implementation CLI (such as score-helm) to a teams CI toolset. This allows to execute Score automatically and possibly trigger deployments directly from a CI pipeline.

[Nitishupkr]

can u give permission to contribute in this repo

[rachfop]

Hey, @Nitishupkr I looked into the permissions for our repos. Anyone should be able to submit a PR. Feel free to look at the doc repo for a great first PR.

[sujaya-sys]

https://github.com/score-spec/setup-score