## New undo step on changing selection ([#20](https://github.com/ckeditor/ckeditor5-typing/issues/20))

*Every selection change should create a new undo step.*

**Check**:

1. Type "aaa" in one place.
1. Move selection to another.
1. Type "bbb".
1. Move selection to another place.
1. Type "ccc".
1. Undo 3 times.

**Expected**:
3 undo steps were created. It is possible to undo 3 times, each time 3 letters from steps 5, 3, 1 are undone.
