Merge pull request #70 from jestin/master

Add vim keys as alternative to arrow key navigation

src/Mapscii.js

@@ -208,15 +208,19 @@ class Mapscii {
         this.zoomBy(-config.zoomStep);
         break;
       case 'left':
+      case 'h':
         this.moveBy(0, -8/Math.pow(2, this.zoom));
         break;
       case 'right':
+      case 'l':
         this.moveBy(0, 8/Math.pow(2, this.zoom));
         break;
       case 'up':
+      case 'k':
         this.moveBy(6/Math.pow(2, this.zoom), 0);
         break;
       case 'down':
+      case 'j':
         this.moveBy(-6/Math.pow(2, this.zoom), 0);
         break;
       case 'c':