Improve middleware documentation

The middleware documentation briefly mentions that dioxus works with tower middleware, but it doesn't go into detail about how to use tower middleware. It would be nice to add information about:
- Common tower middleware crates (tower-http)
- How to implement your own tower middleware (or at least link to towers documentation about this)

Locate the existing middleware documentation and review the linked or relevant Tower documentation before editing. Add coverage of common Tower middleware crates such as tower-http and explain how to implement custom Tower middleware, or link to Tower's documentation; done means both requested topics are covered.

Written by the indexing model from the issue text.