Examine source code of Askbot unseen posts

{
  "manifest_version": 2,
  "name": "Askbot unseen posts",
  "description": "Highlights unseen posts on Askbot sites.",
  "version": "3.0.0",
  "author": "DaveRo",
  "applications": {
    "gecko": {
      "id": "jolla_askbot_unseen_posts@davero.addons.mozilla.org"
    }
  },
  "background": {
    "scripts": [
      "index.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "storage",
    "webNavigation"
  ]
}