Examine source code of Impressieve extension

{
  "manifest_version": 2,
  "name": "__MSG_appName__",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "version": "0.1.3",
  "icons": {
    "16": "icons/logo16.png",
    "19": "icons/logo19.png",
    "32": "icons/logo32.png",
    "48": "icons/logo48.png",
    "64": "icons/logo64.png",
    "128": "icons/logo128.png",
    "180": "icons/logo180.png",
    "512": "icons/logo512.png"
  },
  "browser_action": {
    "default_icon": "icons/logo48.png",
    "default_title": "Impressieve",
    "default_popup": "popup/index.html"
  },
  "permissions": [
    "storage",
    "activeTab",
    "webRequest",
    "tabs",
    "webRequestBlocking",
    "webNavigation",
    "*://confirmemail.impressieve.com/*",
    "https://api.impressieve.com/*"
  ],
  "web_accessible_resources": [
    "confirm/email.html",
    "css/*",
    "fonts/*",
    "icons/impressieve-logo-01.svg"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "testadd@impressieve.com"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "file://*/*",
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/content_coop.js",
        "scripts/content_local.bundle.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    },
    {
      "matches": [
        "file://*/*",
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/content_uncoop.js"
      ],
      "css": [
        "css/impressieve.css"
      ],
      "run_at": "document_end",
      "all_frames": false
    }
  ],
  "background": {
    "scripts": [
      "scripts/communication.bundle.js"
    ]
  }
}