Learn the fundamentals of DAML online: Choices and Role pattern

We have another excellent tutorial on DAML fundamentals thanks to @drsk
This time we’re covering an important topic of choices and role pattern as well as what are consuming and nonconsuming choices:

nonconsuming choice doesn’t affect the contract it’s contained in. You can execute it as many times as you want. In contrast, a consuming choice can be called exactly once. As soon as the call happens, the containing contract is marked as inactive and a subsequent call will fail.

This is great @nemanja and good job @drsk!