RTD fails

[orbeckst]

RTD does not build

Error

Problem in your project's configuration. No default configuration file found at repository's root.

https://readthedocs.org/projects/mdanalysisdata/builds/22389205/

[orbeckst]

... and the docs workflow also fails https://github.com/MDAnalysis/MDAnalysisData/actions/runs/6695446777

error: invalid command 'build_sphinx'

[orbeckst]

I raised #66 as a separate issue as these seem to be two different things.