add keyboard shortcuts

[jxhug]

tasks are:

• ⌘ + f to filter games list (search through games list #42)
• ⌘ + n to add a new game
• ⌘ + e to edit a game
• ⌘ + p to play a game
• ⌘ + 1-4 to switch sorting categories

[Shock9616]

What would be the purpose of adding tabs? It seems to me like it's an unnecessary complication since they're generally used for multitasking (like editing 2 files or having 2 websites open). There's not really any point I can think of to add them.

I agree with the rest of the shortcuts though. The add/edit commands should probably also be added to the right-click menu in the games list and the file menu in the menu bar.

[jxhug]

yeah i deleted those. not necessary

[jxhug]

done in #52