Update README.rst

Author: hmacdope

README.rst

@@ -3,7 +3,7 @@ pytng - A python library to read TNG files!
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 .. image:: https://github.com/MDAnalysis/pytng/workflows/build/badge.svg
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+.. image:: https://github.com/MDAnalysis/pytng/workflows/docs/badge.svg
 .. image:: https://codecov.io/gh/MDAnalysis/pytng/branch/master/graph/badge.svg
   :target: https://codecov.io/gh/MDAnalysis/pytng
 .. image:: https://zenodo.org/badge/92180386.svg