Integrate with Spyder and docrepr

Nice to see that somebody implemented reST editor for PySide.

I was missing this functionality in Spyder, so it would be nice to pack it as a plugin or something.

There is a also an object inspector interface that can benefit from markup edition abilities.
https://github.com/spyder-ide/docrepr and https://github.com/spyder-ide/docrepr/pulls

Start by reviewing the sphinx-gui project and the linked docrepr repository and pull requests. Clarify the intended Spyder plugin or object-inspector integration, then define completion as an agreed integration path with working markup editing support in Spyder.

Written by the indexing model from the issue text.