Examine source code of Quick prompt manager

{
  "manifest_version": 2,
  "name": "MidJourney Companion (unofficial)",
  "version": "1.0.0",
  "description": "Quick prompt manager and helper tools for MidJourney users. Unofficial — not affiliated with MidJourney.",
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "clipboardWrite"
  ],
  "icons": {},
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "MidJourney Companion",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ],
      "css": [
        "inject.css"
      ]
    }
  ],
  "applications": {
    "gecko": {
      "id": "midjourney-companion@example",
      "strict_min_version": "60.0"
    }
  }
}