WIP Reference docstrings for markdown documentations

[ptbrowne]

It is quite useful to reference docstrings inside tutorials. This PR brings this functionality by implementing a custom markdown extension.

The extensions bases itself on thee sphinxjs python module which provides extraction and indexing of the docstrings.

The result is that you can write

## Konnector tutorial

For 2FA you should use the waitForTwoFaCode function.

---> BaseKonnector#waitForTwoFaCode

and ---> BaseKonnector#waitForTwoFaCode will be replaced by :

I made this PR a WIP because I want to gauge interest for it. I would welcome anybody testing the PR on his local machine also.

[nono]

Ping @ptbrowne

[ptbrowne]

I think I was waiting for a review on this, I still think that it could be interesting to have this kind of functionality, particularly for technical tutorials where we explain the role of functions, like for connectors.