code cleanup

src/library.js

@@ -109,8 +109,7 @@ function gamesFollowingDefault(running) {
   })
 }
 
-// Windows is the default: entries written before Linux apps existed have no
-// kind at all.
+// `kind` is only ever written as 'linux'; a missing one is a Windows app.
 function isLinuxGame(game) {
   return !!game && game.kind === 'linux'
 }