Django-tailwind

- Enables Purge CSS by default in Tailwind CSS v2 template
- Improves Windows support

- Adds support for Tailwind CSS 2.0
- Moves Tailwind CSS 1.0 support under `--legacy` flag

- Adds `manage.py tailwind check-updates` and `manage.py tailwind update` commands

- Updates tailwindcss to 1.9.6
- Updates tailwind.config.js

- Adds Django 3.1 support
- Adds Purge CSS support and instructions
- Fixes failing tests, we're green now!
- Updates tailwindcss to 1.6.2
- Updates tailwind.config.js

- Updates script commands in package.json
- Fixes SASS support