Add examples for common usage

[mehcode]

Add usage examples for common scenarios. The idea here is to get the example working and then work towards making the example feel ergonomic.

• [ ] diesel - Requires integration of futures-cpupool (or similar)
• [x] postgres-tokio
• [ ] File upload through multipart forms
• [x] Redirect ( from @Meralis40 )
• [ ] Static Files - Investigate AIO and benchmark against a threadpool + std IO
• [ ] Reading and writing Cookies
• [ ] Session management