include source code in published packages

[DetachHead]

fixes #279

[codecov]

Codecov Report

Merging #280 (8132182) into master (9511b66) will not change coverage.
The diff coverage is n/a.

❗ Current head 8132182 differs from pull request most recent head 223a3bd. Consider uploading reports for the commit 223a3bd to get more accurate results

@@            Coverage Diff            @@
##            master      #280   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           17        17           
  Lines          418       418           
  Branches        63        63           
=========================================
  Hits           418       418           

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