Expand documentation

[christian-byrne]

Can we improve the documentation slightly by

• Adding https://www.notion.so/drip-art/Draft-ComfyUI-Vue-Custom-Node-Development-Tutorial-2006d73d365080c38057d400b9c13926 to https://github.com/Comfy-Org/docs
• Linking to the docs page in the README
• (Optional) Explaining briefly that this is a template repo and that the user can change the implementation with their own Vue component -- and is meant to use the template as a guide for how to handle everything else.