Custom Add-On Documentation

[jherr]

Which project does this relate to?

Create Tanstack App

Describe the bug

We should have a thorough walkthrough of how to create a custom add-on using pnpx create-tsrouter-app@latest add-on init and pnpx create-tsrouter-app@latest add-on compile.

Your Example Website or App

https://github.com/TanStack/create-tsrouter-app

Steps to Reproduce the Bug or Issue

1. Go to the project and look for documentation for creating add-ons

Expected behavior

You find some good documentation.

Screenshots or Videos

No response

Platform

• OS: [e.g. macOS, Windows, Linux]
• Browser: [e.g. Chrome, Safari, Firefox]
• Version: [e.g. 91.1]

Additional context

No response