New instance creation in sequence diagrams

[ltzehan]

I think the <<create>> syntax is fine even though it is not standardized in this module. However, in line with the reference material, the arrow representing the constructor should be at the side of the box representing the instance:

Instead, the sequence diagrams have lifelines that start before the constructor call:

[nus-pe-script]

Your response not required for this bug as the team has accepted the bug as it is.