Move remaining content out of articles directory

Author: parlough

firebase.json

@@ -32,9 +32,12 @@
       { "source": "/api", "destination": "https://api.dart.dev", "type": 301 },
       { "source": "/articles", "destination": "https://medium.com/dartlang", "type": 301 },
       { "source": "/articles/api-naming-guide{,/**}", "destination": "/effective-dart/design", "type": 301 },
+      { "source": "/articles/archive", "destination": "https://medium.com/dartlang", "type": 301 },
+      { "source": "/articles/archive/converters-and-codecs", "destination": "/libraries/convert/converters-and-codecs", "type": 301 },
       { "source": "/articles/archive/dart-2", "destination": "/guides/language/evolution#dart-20", "type": 301 },
       { "source": "/articles/archive/event-loop", "destination": "https://medium.com/dartlang/dart-asynchronous-programming-isolates-and-event-loops-bffc3e296a6a", "type": 301 },
       { "source": "/articles/archive/numeric-computation", "destination": "/guides/language/numbers", "type": 301 },
+      { "source": "/articles/archive/zones", "destination": "/libraries/async/zones", "type": 301 },
       { "source": "/articles/await-async", "destination": "/codelabs/async-await", "type": 301 },
       { "source": "/articles/broadcast-streams", "destination": "https://medium.com/dartlang/dart-asynchronous-programming-streams-dab952023ed7", "type": 301 },
       { "source": "/articles/converters-and-codecs", "destination": "/articles/archive/converters-and-codecs", "type": 301 },