Add documentation on PDC data permissions

[bickelj]

Issue #1291

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.89%. Comparing base (ff39cb2) to head (63f78d7).
Report is 2 commits behind head on main.

Additional details and impacted files

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  Coverage   86.89%   86.89%           
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  Files         213      213           
  Lines        2633     2633           
  Branches      345      345           
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  Hits         2288     2288           
  Misses        315      315           
  Partials       30       30           

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[slifty]

This looks really really good thank you for documenting it so clearly.

I had one question about the semantic linking between keycloak organization and funder / changemaker / data provider in the PDC. If there is no use case for that right now we might consider removing it from the documentation entirely to make it clearer that the way you assign permissions to members of a keycloak organization is via PDC userGroups