Examine source code of Styling

{
  "name": "Styling",
  "short_name": "Styling",
  "author": "James Douglas",
  "description": "__MSG_description__",
  "manifest_version": 2,
  "version": "0.13.3",
  "icons": {
    "128": "images/Styling.png"
  },
  "options_ui": {
    "page": "src/options.html",
    "chrome_style": false
  },
  "default_locale": "en",
  "applications": {
    "gecko": {
      "id": "{4acf1e87-8461-4606-a7c4-d4890aa2147a}"
    }
  },
  "browser_action": {
    "default_icon": {
      "128": "images/Styling.png"
    },
    "default_title": "Styling",
    "default_popup": "src/popup.html"
  },
  "permissions": [
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "web_accessible_resources": [
    "images/Styling.png",
    "images/StylingDisabled.png",
    "src/inject.js",
    "src/popup.js",
    "src/popup.html",
    "src/manage.js",
    "src/manage.html",
    "Roboto-Light.ttf"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true,
      "js": [
        "src/jquery-3.4.1.min.js",
        "src/inject.js"
      ]
    }
  ]
}