Examine source code of Mute by Keywords

{
  "manifest_version": 2,
  "name": "Mute by Keywords",
  "version": "1.0",
  "description": "Mute websites if their title contains specific keywords.",
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Mute by Keywords",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{df035df3-cb01-48da-9b03-59f375f40cb5}"
    }
  }
}