Examine source code of SideKick WA

{
  "manifest_version": 3,
  "name": "__MSG_appName__",
  "version": "1.2.0",
  "description": "__MSG_appDesc__",
  "default_locale": "en",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "tabs"
  ],
  "host_permissions": [
    "https://web.whatsapp.com/*"
  ],
  "background": {
    "scripts": [
      "shared/settings.js",
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "sidekick-wa@extensions.yavuz",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "commands": {
    "toggle-privacy": {
      "suggested_key": {
        "default": "Alt+Shift+P",
        "mac": "Alt+Shift+P"
      },
      "description": "__MSG_privacy_toggle_cmd__"
    }
  },
  "action": {
    "default_title": "__MSG_appActionTitle__",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png"
    }
  },
  "options_ui": {
    "page": "options/options.html",
    "open_in_tab": true
  },
  "content_scripts": [
    {
      "matches": [
        "https://web.whatsapp.com/*"
      ],
      "js": [
        "shared/settings.js",
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "icons/*"
      ],
      "matches": [
        "https://web.whatsapp.com/*"
      ]
    }
  ]
}