Toast UI Editor Cursor focus jumping

Summary

Investigate why the cursor jumps to the end of the content in WYSIWYG mode after the first input

Steps to reproduce

(How one can reproduce the issue - this is very important)

1. Use static site editor
2. Make one edit in initial WYSIWYG mode
3. Make a second edit

Bug: Take note that the second edit occurs at the end of the content as the (assumingly) internal cursor of Toast UI editor jumps to the end of the content

@jeanduplessis I assigned you for prioritizing, I'm assuming this is a simple fix but I haven't dug into it. I was going to self-assign (and feel free to), but I feel like a bunch of issues are stacking up on my plate.