Remove bad trailing comma (#1737)

Also removed the comments since they look bad in the GitHub UI

Author: samtstern

.opensource/project.json

@@ -8,19 +8,16 @@
 
     "content": "README.md",
 
-    // Other markdown pages that should be rendered nicely
     "pages" : [
         "ROADMAP.md",
         "Carthage.md",
         "CONTRIBUTING.md",
         "CODE_OF_CONDUCT.md"
     ],
 
-    // Related projects on Github, in the format $owner/$repo[/$subproject]
-    // where subproject is optional.
     "related": [
       "firebase/quickstart-ios",
       "firebase/firebaseui-ios"
-    ],
+    ]
 
 }