Examine source code of CSS Injector

{
  "name": "CSS Injector",
  "short_name": "Rapid Style",
  "version": "0.5.5",
  "description": "Rapidly edit custom style of webpage",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "background": {
    "page": "rapidfix.html"
  },
  "browser_action": {
    "default_title": "CSS Injector",
    "default_icon": "icon48.png"
  },
  "applications": {
    "gecko": {
      "id": "@cssinjector",
      "strict_min_version": "57.0"
    }
  },
  "permissions": [
    "tabs",
    "*://*/*",
    "contextMenus",
    "storage",
    "unlimitedStorage",
    "activeTab",
    "clipboardWrite",
    "clipboardRead"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "css": [
        "data/addon/css/editor.css",
        "data/shared/icons/pe-icon-7-stroke.css"
      ],
      "js": [
        "data/addon/port-wrapper.js",
        "data/addon/rapidfix-browser.js",
        "data/shared/libs/jquery-3.5.1.js",
        "data/shared/overlay.js"
      ]
    }
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "web_accessible_resources": [
    "editor.html",
    "data/shared/icons/pe-icon-7-stroke.css",
    "data/shared/icons/Pe-icon-7-stroke.ttf",
    "frame.html"
  ],
  "manifest_version": 2
}