Add support for activation of virtual environment

[e-d-n-a]

I guess, one aspect of using WinPython e.g. is, that you can prepare multiple installations (portable) and use then for different purposes.
This could be for different Python-versions or packages etc.

Your context menu structure only assumes/allows for a single installation/environment tho!?

[ericpre]

Why are you using different python distribution instead of different environment?
start_jupyter_cm supports links for different conda environment with the name of the environment in brackets. I am familiar with venv but I guess it shouldn't be that complicated to add support for it. I suspect that it is already partially working because it would point to correct entry point but the environment is not be activated.

In case of different python distribution, how should the name of the python distribution be differentiated from each other in the context menu?