Apologies that the version 10 Documentation is not yet available. It should be ready soon.
A Quick Action allows you to create a macro to perform any repetitive actions, so a sequence of steps. These are the functions you can choose from:
For example, you can create a Quick Action to forward a message to a specified address, choose to be notified when you get a reply and send it. Then move the original message to a specified folder, add tag it.
So like this:
You can execute it by selecting a message then either by clicking on the Quick Action from a list, or assigning a keyboard shortcut to the Quick Action.