Examine source code of Manga Sync

{
  "manifest_version": 3,
  "name": "Manga Sync",
  "version": "1.4.1",
  "description": "Manage and sync your manga reading progress",
  "icons": {
    "48": "icons/icon-48.svg"
  },
  "permissions": [
    "storage",
    "contextMenus",
    "scripting",
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_icon": {
      "48": "icons/icon-48.svg"
    },
    "default_title": "Manga Sync"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "manga-sync@example.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "content-add-manga.js",
        "content-add-manga.css"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}