docs(maintainer): add maintainer governance docs

[d33bs]

Description

This PR adds documentation covering project roles and how to become a maintainer.

Closes #328

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• Bug fix (fixes an issue).
• Enhancement (adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.74%. Comparing base (b558b39) to head (7ce8e1c).

Additional details and impacted files

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  Coverage   94.74%   94.74%           
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  Files          57       57           
  Lines        3156     3156           
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  Hits         2990     2990           
  Misses        166      166           

Flag	Coverage Δ
unittests	94.74% <ø> (ø)

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[gwaybio]

I like the language additions here. I wonder if we should include a maintainer offboarding process as well.

I imagine this would be a voluntary decision, but are there any other scenarios that we should delineate for offboarding?

[d33bs]

Thanks @gwaybio ! Good thoughts on adding an offboarding process. I imagine you're correct - that this would usually be a voluntary process. While a bit dark, another scenario might be if we know someone has passed away (we might want to demote the account to help avoid unwanted activity should their account be hijacked).

We could get more thorough here and think through if we want to remove maintainers based on inactivity, but I don't know how to make that process fair and useful at this time. PEP 13 highlights an ejection process that might be helpful; maybe we could adopt something like this to be on the safe side (two-thirds vote to eject from other existing maintainers means involuntary offboarding of maintainer status within Pycytominer). We could peel this off into another issue for further discussion. Thoughts?