Added double island and harder island to blueprint bundles.

src/main/resources/blueprints/double_island.json

@@ -0,0 +1,16 @@
+{
+  "uniqueId": "double_island",
+  "icon": "FURNACE",
+  "displayName": "Double Island",
+  "description": [
+    "Two islands in one!",
+    "Can you reach the",
+    "desert?"
+  ],
+  "requirePermission": false,
+  "blueprints": {
+    "NORMAL": "double",
+    "NETHER": "nether-island",
+    "THE_END": "end-island"
+  }
+}

src/main/resources/blueprints/harder_island.json

@@ -0,0 +1,16 @@
+{
+  "uniqueId": "harder_island",
+  "icon": "SNOWBALL",
+  "displayName": "Harder Island",
+  "description": [
+    "This island is",
+    "much harder.",
+    "Beware the lava!"
+  ],
+  "requirePermission": false,
+  "blueprints": {
+    "NORMAL": "harder",
+    "NETHER": "nether-island",
+    "THE_END": "end-island"
+  }
+}