Improve documentation to make all information available in a single view

[Raynos]

This would solve...

I found it challenging to navigate the documentation and understand how to do things like

• What are all the options available to request()
• I have an old legacy streams1 package, how do I create a req instance and do oldstream.pipe(req) to write the HTTP body

The implementation should look like...

https://github.com/request/request#requestoptions-callback

I have also considered...

Not using undici, and using another package with a more user friendly README

Additional context

All the documentation is there, I just have to click around and read multiple pages and multiple sections and its very confusing,

• https://github.com/nodejs/undici/blob/main/docs/api/Dispatcher.md#parameter-requestoptions
• then click https://github.com/nodejs/undici/blob/main/docs/api/Dispatcher.md#parameter-dispatchoptions
• but also i had to click https://github.com/nodejs/undici/blob/main/docs/api/Dispatcher.md#dispatcherrequestoptions-callback

[mcollina]

A massive overhaul of our docs is welcomed, but at this point it seems a stretch for the current team. I would love if somebody volunteered for this effort.