Documentation: tip, how to copy request from a browser or Wireshark

[JulioJu]

Hi !

Maybe it could be cool to add a Tip to say how to copy an HTTP header of a request with Wireshark.

As it, when a server generate a Request, we could see what is the request and copy it in a roast file.

The tip could be something like:

Start Wireshark and configure the capture

1. ...using this filter tcp port 3030 (where 3030 is the targeted server port. Reminder, if the url has no port, then it's the port 80 that is used).
2. Use interface Loopback:lo (if the server is at localhost, if it's on the web use the corresponding interface. If you don't know which interface use, skip this step)
3. menu -> capture -> start
4. In « Apply a display filter », type http

To copy the request in Wireshark

1. double click on the row of the green pan
2. A new window appears with two pans
3. On the top pan, unfold « Hyptertext Transfer Protocol »
4. Select the blue link « [Full request URI: http://localhost…] »
   (as it we are sure
   that we are on the second tab named « Reassembled TCP »).
5. On its bottom pan righ click anywhere
6. contextual menu appears
7. copy
8. as Printable text

• Note: on Wireshark, Unicode and not printable characters are represented by
  the symbole  . . It's not a problem, when you copy it in Vim the correct
  corresponding symbols are represented.

For the browser, simply give a link to https://developer.mozilla.org/en-US/docs/Tools/Network_Monitor/request_details and https://developers.google.com/web/tools/chrome-devtools/network/#details and say that we could simply copy the request pan and past to the roast file.

If you are ok I could make the PR.