Add dev setup info for Windows/WSL

# 💡 Summary #

Add some documentation for how to set up common tools for a development environment on Windows.

## Motivation and context ##

Several people who work with our GitHub tooling are required to use Windows. Some of these users are also limited from installing some kinds of software without justifications/approval. Let's provide some guidance about how to do things anyway, such as:

- [Windows Subsystem for Linux (WSL)](https://docs.microsoft.com/en-us/windows/wsl/install-win10)
- Docker-based development images

## Implementation details ##

This should be added to the [dev_envs list](https://github.com/cisagov/development-guide/tree/develop/dev_envs).

## Acceptance criteria ##

How do we know when this work is done?

- [ ] Documentation for how to setup and run standard skeleton tools on a Windows-based machine