Examine source code of Chess Image Importer

{
  "manifest_version": 2,
  "name": "Chess Image Importer",
  "version": "1.1.3",
  "icons": {
    "16": "/pawn-16.png",
    "48": "/pawn-48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "chess-image-importer@osifeddine.local",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "contextMenus",
    "activeTab",
    "storage",
    "scripting",
    "http://*/*",
    "https://*/*"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Target Site",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}