[Documentation] Add documentation about how to create a new Github repo

[dmvt]

There are several steps involved in properly setting up a new Github repo, including adding the Discord webhook, configuring branch protection, creating a development branch, and copying the issue templates from the meta repo.

User Story

• As an <audience/user>: developer
• I want to <action/task>: have a clear checklist / guide for creating a new repo
• so that <outcome/goal/benefit>: everything gets set up properly

Type

• Enhancement
• Maintenance
• Refactor

Description

There are enough steps now that it's not easy for everyone to remember what to do when creating a new repo. As we add team members, this will become harder.

Definition of Done

• There's a new page under the development resources section title Github Setup
• This page includes walkthrough of all the required setup steps

Attach files or screenshots if it's helpful for this issue.