fix: correct formatting of rewrites section in firebase.json (#1031)

Author: lacolaco

firebase.json

@@ -48,7 +48,7 @@
           }
         ]
       },
-            {
+      {
         "source": "**/*.html",
         "headers": [
           {
@@ -84,12 +84,12 @@
           }
         ]
       }
+    ],
+    "rewrites": [
+      {
+        "source": "**",
+        "destination": "/index.html"
+      }
     ]
-  },
-  "rewrites": [
-    {
-      "source": "**",
-      "destination": "/index.html"
-    }
-  ]
+  }
 }