**Is your feature request related to a problem? Please describe.**

Currently, the only way to show the About panel on macOS is by creating a `{role: 'about'}` menu item and click it. I need to be able to show it manually.

**Describe the solution you'd like**

Electron already has the method, so it's just about exposing this to JS and documenting it:

https://github.com/electron/electron/blob/8ba271efba691357ab1970c1a553b4e019125574/atom/browser/browser_mac.mm#L376

Would also be useful to be able to pass in the panel options directly to the method to override the defaults.

I would call the method: `app.showAboutPanel(options)`

**Describe alternatives you've considered**

None.
atom/browser/api/atom_api_app.cc
Emit("accessibility-support-changed", IsAccessibilitySupportEnabled());
}
#if defined(OS_MACOSX)
void App::OnWillContinueUserActivity(bool* prevent_default,
                                     const std::string& type) {
  if (Emit("will-continue-activity", type)) {
    *prevent_default = true;
  }
}
void App::OnDidFailToContinueUserActivity(const std::string& type,
                                          const std::string& error) {
  Emit("continue-activity-error", type, error);
}
void App::OnContinueUserActivity(bool* prevent_default,
                                 const std::string& type,
                                 const base::DictionaryValue& user_info) {
  if (Emit("continue-activity", type, user_info)) {
    *prevent_default = true;
  }
}
void App::OnUserActivityWasContinued(const std::string& type,
                                     const base::DictionaryValue& user_info) {
  Emit("activity-was-continued", type, user_info);
}
void App::OnUpdateUserActivityState(bool* prevent_default,