Hi,
The solution Mohamed gave you was so that the registration page outside of the checkout would be handled by hikaShop instead of Joomla.
This alone wouldn't have fixed the issue of you not getting the email upon registration during the checkout.
So either you fixed the problem differently, or you didn't had the problem at all and just didn't see the email sent by HikaShop before.
There is not one document listing all of the plugins and their functions. However, when you check the documentation for a subject, we will refer to related plugins. For example, on the currency documentation:
www.hikashop.com/support/documentation/2...ies-in-hikashop.html
We talk about the HikaShop currency rates auto refresh plugin as well as the currency switcher module.