Examine source code of softdict for firefox

{
  "name": "softdict for firefox",
  "description": "read text on mouse cursor and send to my dictionary program.",
  "version": "1.0",
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "{eaba9742-33f4-4a02-a3de-447f3b2bb1e5}",
      "strict_min_version": "109.0"
    }
  },
  "icons": {
    "16": "cap16.png",
    "48": "cap48.png",
    "128": "cap128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_icon": {
      "19": "cap19.png",
      "38": "cap38.png"
    },
    "default_popup": "capturePopup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self' 'wasm-unsafe-eval'; object-src 'none'"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ]
}