Use 'pt' instead of 'px' for font sizes

src/app/editor.coffee

@@ -630,7 +630,7 @@ class Editor extends View
 
   setFontSize: (fontSize) ->
     if fontSize
-      @css('font-size', fontSize + 'px')
+      @css('font-size', fontSize + 'pt')
       @calculateDimensions()
       @compositeCursor.updateAppearance()
       @updateVisibleLines()

src/app/root-view.coffee

@@ -28,7 +28,7 @@ class RootView extends View
 
   extensions: null
   extensionStates: null
-  fontSize: 18
+  fontSize: 20
 
   initialize: (pathToOpen) ->
     @extensions = {}