Examine source code of Gmail minimal

{
  "$schema": "https://json.schemastore.org/chrome-manifest.json",
  "manifest_version": 3,
  "version": "1.4.5",
  "name": "Gmail minimal",
  "short_name": "Gmail mini",
  "description": "Modifies Gmail's layout to have more space available: smaller icons, texts, ...",
  "icons": {
    "500": "icons/logo.jpg"
  },
  "content_scripts": [
    {
      "matches": [
        "*://mail.google.com/*"
      ],
      "js": [
        "js/src/common/utils/ExtensionUtil.js",
        "js/src/common/GenericConstants.js",
        "js/src/common/utils/AlertUtil.js",
        "js/src/common/utils/Functions.js",
        "js/src/common/utils/LogUtil.js",
        "js/src/common/utils/StringUtil.js",
        "js/src/common/utils/ColorUtil.js",
        "js/src/common/utils/StorageUtil.js",
        "js/src/common/utils/dom/AbstractDomUtil.js",
        "js/src/common/utils/dom/DomUtil.js",
        "js/src/gmailMinimalConstants.js",
        "js/src/locations/center/gmailMinimalAbstractCenter.js",
        "js/src/locations/center/gmailMinimalCenter.js",
        "js/src/locations/left/gmailMinimalAbstractLeft.js",
        "js/src/locations/left/gmailMinimalLeft.js",
        "js/src/locations/top/settings/beans/gmailMinimalSettingsBean.js",
        "js/src/locations/top/settings/gmailMinimalAbstractSettings.js",
        "js/src/locations/top/settings/gmailMinimalSettings.js",
        "js/src/locations/top/gmailMinimalAbstractTop.js",
        "js/src/locations/top/gmailMinimalTop.js",
        "js/src/gmailMinimalMain.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{60eed593-baba-49f9-b0b2-9db546bb452f}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}