Examine source code of Code Inject

{
  "manifest_version": 2,
  "name": "Code Injector",
  "version": "0.3.4",
  "author": "L. Sabatelli",
  "description": "Inject code into websites! (JavaScript, CSS, HTML and Files)",
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab",
    "storage",
    "webNavigation"
  ],
  "icons": {
    "16": "style/images/icon/icon-16px.png",
    "24": "style/images/icon/icon-24px.png",
    "32": "style/images/icon/icon-32px.png",
    "48": "style/images/icon/icon-48px.png",
    "64": "style/images/icon/icon-64px.png",
    "96": "style/images/icon/icon-96px.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "style/images/icon/icon-16px.png",
      "24": "style/images/icon/icon-24px.png",
      "32": "style/images/icon/icon-32px.png",
      "48": "style/images/icon/icon-48px.png",
      "64": "style/images/icon/icon-64px.png",
      "96": "style/images/icon/icon-96px.png"
    },
    "default_title": "Code Injector",
    "default_popup": "html/browser-action.html"
  },
  "background": {
    "scripts": [
      "script/browser-polyfill.min.js",
      "script/background.js"
    ],
    "persistent": true
  },
  "options_ui": {
    "page": "html/options-ui.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "58.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{d0daeca6-cf65-4432-863e-70bea8da2c4c}"
    }
  }
}