[improvement request] make done tasks strike-through optional

hi,

Can you make strike-through for completed tasks in tasklist optional?

Current behaviour

checked tasks have a text-decoration: line-through; (see image right bottom corner, "Styles").

Environment

• Version : 0.11.9
• OS Version and name : 16.04 Ubuntu

[ZeroX-DG]

Why don't I have that feature???

@ZeroX-DG, I updated the issue to make it more clear what I meant.