Improved documentation + fixed typo

[PicoCentauri]

Description

This PR adds some additional hints for running the bot.

Motivation and Context

Helps people who want to run their own bot.

How Has This Been Tested?

Only docs...

Types of changes

• nginx config page
• notes on configuring the github webhook
• Fixed a typo

[derrod]

I'm gonna merge this with some minor fixes, the typo stuff I'll fix in a general cleanup pass.