Improve instrument documentation
Created originally on Bitbucket by jsalort (Julien Salort)
Was already merged in Bitbucket before import, marked as merged by the import user
In the current documentation, the docstring of instrument features is not rendered, see for example: https://fluidlab.readthedocs.io/en/latest/generated/fluidlab.instruments.multimeter.hp_34401a.html#module-fluidlab.instruments.multimeter.hp_34401a
Sphinx only shows the attribute signature.
It is my understanding that the aim of the file doc/docattributes.py was to fix that, and allows to show the attribute docstring in the documentation. It seems that it does not work because attribute objects do not trigger ‘autodoc-process-docstring’ event.
Therefore, I propose to change instead the attribute signature, and show the docstring in the return annotation. I also propose that it is more informative to show the short name of the class in the rhs.