Fixed small issues and added hotkeys

response panel was showing incorrectly on small resolutions
updated to match original coding style
added hotkeys for url bar, request send and parameter adding
replaced buttons using <a> elements with actual button elements in order
not to unnecessarily change the URL
changed default active response tab to the actual result
removed CSS part from the Get Involved section in the readme file
Merge pull request #22 from revolt666/master

Fixed small issues and added hotkeys.