Log Message:
py36-html-docs: Update py36-html-docs to 3.6.3

pkgsrc changes:
 - Take MAINTAINERship (or, in other words, make me blameworthy if the Python
   documentation isn't synced with the respective lang/python* packages :))

Changes:
No changelog is available but it syncs py36-html-docs to current
python36 version.