Add profile indicator feature

This experimental feature adds an indicator dot next to the OP's
username in order to indicate whether the OP has participated in more
threads in the same forum.

The dot can indicate the following states:
* Blue: the OP has only participated in the current thread.
* Orange: the OP has participated in other threads, but at least the
last 5 ones have been read by the user.
* Red: the OP has participated in other threads, some of which haven't
yet been read by the user.

Change-Id: Ib358d88dacfe0e713247d7757cf7eea1a2b4f8e9
diff --git a/templates/manifest.gjson b/templates/manifest.gjson
index 2927deb..cfb5ff1 100644
--- a/templates/manifest.gjson
+++ b/templates/manifest.gjson
@@ -40,6 +40,10 @@
     "https://support.google.com/*/thread/*",
     "storage"
   ],
+  "web_accessible_resources": [
+    "console_profileindicator_inject.js",
+    "console_profileindicator_inject.css"
+  ],
   "browser_action": {},
 #if defined(CHROMIUM)
   "options_page": "options.html",