Examine source code of Marklet

{
  "manifest_version": 3,
  "name": "Marklet",
  "version": "1.2.5",
  "description": "Highlight and annotate web pages with marker-style overlays and freehand drawings.",
  "permissions": [
    "storage",
    "activeTab",
    "contextMenus",
    "scripting",
    "unlimitedStorage",
    "webNavigation"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_ui": {
    "page": "settings/settings.html",
    "open_in_tab": true
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "utils/tiny-idb.js",
      "utils/page-storage.js",
      "utils/consts.js",
      "utils/shared.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "marklet@rz-extensions.local",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "match_origin_as_fallback": true,
      "js": [
        "utils/tiny-idb.js",
        "utils/page-storage.js",
        "utils/shared.js",
        "utils/consts.js",
        "utils/ui-shared.js",
        "content/assets.js",
        "content/dom_utils.js",
        "content/ui.js",
        "content/whiteboard.js",
        "content/highlighter.js",
        "content/marklet.js"
      ]
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}