Support Sphinx >3.0.0 #37
Description
Since Sphinx moved to 3.0.0, the current documentation build fails because:
/yangify/yangify/linter/__init__.py:docstring of yangify.linter.LinterResult.children:1:duplicate object description of yangify.linter.LinterResult.children, other instance in api/linter, use :noindex: for one of them
Makefile:62: recipe for target 'sphinx_test' failed
This new warning raised by Sphinx, also mentioned in googleapis/synthtool#593, is due to the nested children.
I found this issue while working on #36 and decided to leave the PR with Sphinx pinned to <3.0.0 and open this bug to track independently.