Managing community feedback and contributions

[M-casado]

Hi there, it seems that the contributions documentation is yet to be done, but the number of feedback and contributions (especially through GH issues) is on the rise. As a method of improving how these contributions are managed, I would recommend the use of Issue and Pull Request templates.

As a side note, feel free (since we have an Apache License) to copy-paste and adapt the ones in EGA's metadata repo. I foresee you having more categories, but the "models" part of Beacon's repo would be similar.