Rewrite readme

[ErikPelli]

Rewrite project readme to include new updates and make it more appropriate.
This PR also updates x/net dependency.

[ErikPelli]

@elazarl what do you think about this new readme? Can it be merged?
Here there is a link with the formatted preview so you can check it better: https://github.com/elazarl/goproxy/blob/rewrite-readme/README.md

[elazarl]

@ErikPelli truly amazing. IMHO italics emphasizes better than code.

Let's merge!

[ErikPelli]

Do you prefer italic style? I could change it if you want

[elazarl]

Do you prefer italic style? I could change it if you want

Let me explain

The proxy itself is simply a net/http handler,

Here it's great to have net/http as code, as this is a piece of code.

The target of this project is to offer an optimized proxy server,

Here optimized is more appropriate, as it is an English word, and not a piece of code that could appear in the source.

Does that make sense?

[ErikPelli]

Does that make sense?

Yes, do you want to make a PR to fix the style where you think this is appropriate or should I change it, if you haven't any time available?

[elazarl]

NM, that's a cool style, and let's keep it as it is for the time being. I like it when your fingerprints are felt over the project.

I'll take the oppurtunity to thank you for the tremndous work and effort you invest in the project. It is felt and is hearwarming.