Examine source code of R2 Capture

{
  "manifest_version": 3,
  "name": "R2 Captura e Gravador de Tela",
  "short_name": "R2 Captura",
  "version": "1.4.0",
  "description": "Capturas, anotações, cores HEX, régua de pixels e gravação local com a assinatura R2 Sistemas.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "R2 Captura",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    }
  },
  "background": {
    "scripts": [
      "assets/background.js"
    ],
    "type": "module"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "downloads",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "assets/content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "commands": {
    "capture-visible": {
      "suggested_key": {
        "default": "Alt+Shift+1"
      },
      "description": "Capturar área visível"
    },
    "capture-full": {
      "suggested_key": {
        "default": "Alt+Shift+2"
      },
      "description": "Capturar página inteira"
    },
    "select-area": {
      "suggested_key": {
        "default": "Alt+Shift+3"
      },
      "description": "Selecionar uma área"
    },
    "toggle-ruler": {
      "suggested_key": {
        "default": "Alt+Shift+4"
      },
      "description": "Ativar régua de pixels"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "techcapture@local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}