[idea] meta insert-operator, insert-at-target dynamically pick start or end

[t9md]

Dynamically pick appropriate operator based on moving destination position from existing

• insert-at-start-of-target
• insert-at-end-of-target

Difficulty to use insert-at-start-of-target and insert-at-end-of-target is.

• It need to decide start or end before specifying target.
• But for me, it is difficult, I sometimes mis-select start or end.