Python support

[coatless]

Add a series of templates for Python actions.

• jupyter
• flask
• fastapi
• gpu-dl
• streamlit
• pyshiny

Base image options:

• condaforge: https://hub.docker.com/r/condaforge/miniforge3
• miniconda3: https://hub.docker.com/r/continuumio/miniconda3 (less likely to use due to the commercial channel restriction).
• Or base Python template? python:version?

No rocker for Python... (Maybe make one?)