Examine source code of Hyper Gwent

{
  "manifest_version": 2,
  "author": "Soreine & Zhouzi",
  "homepage_url": "https://soreine.dev/hyper-gwent",
  "name": "Hyper Gwent",
  "description": "Detects and show tooltips for Gwent cards in the pages you visit.",
  "version": "2.1.2",
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "40": "icon40.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "webNavigation",
    "https://soreine.dev/hyper-gwent/*",
    "https://soreine.github.io/hyper-gwent/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "js": [
        "content.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "32": "icon32.png",
      "40": "icon40.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "web_accessible_resources": [
    "*.png",
    "*.woff2"
  ],
  "applications": {
    "gecko": {
      "id": "extension@hyper-gwent.com",
      "strict_min_version": "57.0"
    }
  }
}