[DOC] Authors page should reflect more than git commit contributions

Brief Description of Fix

Currently, the docs only link to code contributions that involve a git commit. This does not reflect the contributions made by others to the project, such as talks, helping with sprints, social media, and more.

I would like to propose a change, such that now the docs includes at least code sprint contributions. For example, @jk3587 and @sallyhong helped with issues and guiding others at the last sprint at SciPy 2019, @loganthomas and @jekwatt helped others with git at SciPy and PyCon respectively.

Relevant Context

• Link to documentation page: Contributors
• File to be edited: https://github.com/ericmjl/pyjanitor/blob/dev/AUTHORS.rst

[ericmjl]

I think bullet points indicating non-git-commit contributions would be a way out.

[ericmjl]

Yes, indeed, thanks for pointing this out, @hectormz!