use vanilla python/venv in getting started instead of anaconda/conda

[psschwei]

Signed-off-by: Paul S. Schweigert [email protected]

Fixes #1611

Summary

Updates the "Getting Started" locally section to use vanilla Python and venv instead of the Anaconda Python distribution and conda

Details and comments

Updated the references to include links to downloading Python instead of Anaconda. Also added links to install Jupyter docs and the Python venv tutorial. Also updated conda -> pip as appropriate in the "Install from Source" section (with the exception of for Windows, which per the docs requires Anaconda).

[CLAassistant]

All committers have signed the CLA.

[mtreinish]

Oh, as I was going to merge I just noticed the details in the PR summary about installing from source section for windows requiring Conda. I don't know where that requirement in the documentation came from, but there isn't anything on windows I'm aware of that requires conda. I was able to install qiskit from source on my windows test vm with just mvsc and rust installed via pip without anything extra pretty easily. So we can probably just remove that line and update the commands to be pip based too.