Add 'archive' tag to RWDevCon (#2077)

Author: dkhamsing

contents.json

@@ -1889,7 +1889,7 @@
       "source": "https://github.com/kodecocodes/RWDevCon-App",
       "itunes": "https://apps.apple.com/app/rwdevcon-tutorial-conference/id958625272",
       "tags": [
-        "swift"
+        "swift", "archive"
       ],
       "screenshots": [
         "https://is4-ssl.mzstatic.com/image/thumb/Purple128/v4/5c/4c/2d/5c4c2da8-6986-3bdc-25e5-a919fe3f7b9a/pr_source.png/460x0w.jpg",