added konami code easter egg

after pressing the keys "up, up, down, down, b, a" 
* the doge image is replaced with an angry doge
* the doge image is shaken with a css3 transition
* the words that show up on the screen are replaced with 
  * so bite
  * very konami
  * 10/10 sekret
  * not fun
  * many anger
  * such egg
  * wow