Ability to delete tiles

[VAdaPEGA]

Self Explanatory, being able to delete certain tiles (without removing all unused tiles) or add tiles arbitrarily would be nice to have as I've found myself needing that function quite a few times.

[kirjavascript]

You should already be able to add tiles arbitrarily?nt5 for example adds 5 new tiles.

I didn't think there were many useful circumstances outside of deleting unused tiles, but I suppose there could be? I can add it to the next version if so.