Consider simplifying authors attribution

[xamanu]

Is your feature request related to a problem? Please describe.

Currently, authors and thus copyright holders are managed and differ on a file base.

Describe the solution you'd like

One improvement I could imagine, is to give the contributors a name: e.g. pygeoapi development team and license the software with all it's files under this term. In addition an AUTHORS file could give attribution to the members of the team.

Describe alternatives you've considered

Using a consistent author and copyright statement listing all authors and the year range of contribution on all files.

Additional context

Having copyright handled on a whole-software level, instead of a file-level, will make it much easier to create a valid copyright file to the Debian package.