Added some more topics to minesweeper

;)

config.json

         "integers",
         "matrices",
         "games",
-        "conditionals"
+        "conditionals",
+        "strings",
+        "lists"
       ],
       "unlocked_by": "scrabble-score",
       "uuid": "416a1489-12af-4593-8540-0f55285c96b4"