docs/requirements-docs.txt

   1 sphinx>=4.2.0  # BSD
   2 sphinx-rtd-theme>=1.0.0  # MIT
   3 sphinxcontrib-blockdiag  # BSD
   4 sphinxcontrib-seqdiag # BSD
   5 sphinxcontrib-swaggerdoc
   6 sphinxcontrib-spelling
   7 sphinxcontrib-plantuml
   8 six