Document .env file requirements

[fisher60]

sample .env:

# Django settings

DEBUG=True
DJANGO_SECRET_KEY=notasecretbutitstillworksasasecretshrug
POSTGRES_DB=postgres
POSTGRES_HOST=localhost
POSGRES_PASSWORD=postgres
POSTGRES_USER=postgres
DEBUG_HOST=127.0.0.1
ALLOWED_HOSTS=localhost,friendo-site
HOST_DNS=http://127.0.0.1:8000

# Discord Oauth
BOT_CLIENT_ID=your_discord_bot_client
DISCORD_AUTH_URL=your_discord_auth_url

BOT_CLIENT_SECRET=your_client_secret_here

Instructions also need to be added on getting the discord bot secrets. Such as building the auth url with scope=identify