Bugfix: Adding tests and warnings to docs

[Magnus167]

Adding flake8 to docs publish & test workflows.
Adding a failure warning when a file cannot be parsed.

[codecov]

Codecov Report

Merging #960 (d8ec30d) into develop (ee08018) will not change coverage.
Report is 3 commits behind head on develop.
The diff coverage is n/a.

❗ Current head d8ec30d differs from pull request most recent head 348ff89. Consider uploading reports for the commit 348ff89 to get more accurate results

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #960   +/-   ##
========================================
  Coverage    66.59%   66.59%           
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  Files           38       38           
  Lines         4425     4425           
========================================
  Hits          2947     2947           
  Misses        1478     1478