Simplify examples tasks in nico.nimble

[cxong]

Not sure if some of the custom arguments are important; replaced all the single example tasks with a loop that compiles all examples Also added examplesd to compile with debug

[ftsf]

Platformer does require multimethods to function correctly. But simplifing these makes sense, we can use a platformer.nim.cfg or .nims to set the arguments for platformer