Add IDE bindings for epidata development

[rzats]

Prerequisites:

• Unless it is a documentation hotfix it should be merged against the dev branch
• Branch is up-to-date with the branch to be merged with, i.e. dev
• Build is successful
• Code is cleaned up and formatted

Summary

Previously, most IDE features - autocompletion, linting, functioning imports - did not work in epidata due to the codebase's nonstandard structure (pulling code from multiple repos, then reordering them in the Docker container, so the compile-time structure does not match the imports at runtime).

This PR adds a solution that makes IDE development a lot less painful. The idea behind it is to use an "editable install", which is a minimalistic pip package that symlinks to a Python project such that any changes to the package's files are reflected in the dev environment and vice versa. To that end, it

• adds pyproject.toml and setup.cfg files that define how our local package is laid out

• adds some code to the install.sh setup script that symlinks those files to driver/repos

• adds instructions on using these to the README

Caveats:

• pip install -e . --config-settings editable_mode=strict needs to be re-ran when any Python files are added or deleted locally. (But edits to existing files will be reflected in the editable install.)
• The bindings in pyproject.toml need to be updated whenever we add new packages and subfolders. This is due to the following limitation:

Although package_dir applies recursively, you must explicitly list all packages in packages: the Distutils will not recursively scan your source tree looking for any directory with an __init__.py file

[dshemetov]

one small nit, but otherwise lgtm 🚀

good work tracking this all the way to the root issue in setuptools!

[dshemetov]

🚢 🚢 🚢

[krivard]

nice work! and documentation updates too, well done!

[melange396]

very nice!