docs: add CONTRIBUTING.md

CirclonGroup / angular-tree-component

A simple yet powerful tree component for Angular (>=2)

https://angular2-tree.readme.io/docs

MIT License

1.1k stars 492 forks source link

Closed tobiasengelhardt closed 4 years ago

tobiasengelhardt commented 4 years ago

Add contributing file with help and guidelines on how to contribute to angular tree component.