Adding Simple URL-based feature flags (#117)

* Fixes #66: As a developer, I want to limit the audience
that sees new features, so that we can control
the message and positioning of our tool.
Implements simple feature flagging via URL parameters.
Provide "?flags=x,y,z" to enable flags x, y, and z.
* Fixing type to use Location instead of URL
* Updating README with info on how to use feature flags

client/.vscode/launch.json

@@ -29,6 +29,19 @@
       "stopOnEntry": false,
       "runtimeArgs": ["--nolazy"],
       "sourceMaps": false
+    },
+    {
+      "name": "Debug Jest Tests",
+      "type": "node",
+      "request": "launch",
+      "runtimeArgs": [
+        "--inspect-brk",
+        "--inspect",
+        "${workspaceRoot}/node_modules/.bin/jest"
+      ],
+      "console": "integratedTerminal",
+      "internalConsoleOptions": "neverOpen",
+      "port": 9229
     }
   ]
 }