A quick video of Marlin3DprinterTools new Feature => Marlin Configurator.
It is a GUI that reads your old Marlin FW and compare it with the new Marlin 1.1.0
While you check the checkboxes and enter values in textboxes the manual is available in a window on the side. It tries to understand where you are in the process of migration and gives you information of how to configure the features.
I hope it will be in v0.24-beta and be released at the end of May