fix: no cache of index/sw

Author: Kevin Tam

firebase.json

@@ -11,6 +11,26 @@
         "source": "**",
         "destination": "/index.html"
       }
+    ],
+    "headers": [
+      {
+        "source": "index.html",
+        "headers": [
+          {
+            "key": "Cache-Control",
+            "value": "max-age=0"
+          }
+        ]
+      },
+      {
+        "source": "/sw.js",
+        "headers": [
+          {
+            "key": "Cache-Control",
+            "value": "no-cache"
+          }
+        ]
+      }
     ]
   },
   "firestore": {