Characters stays on screen
I'm creating my first Nim app. Illwill seems a great library for achieving it. Thanks for publishing it!

However, when the screen content is updated, some characters of its previous content remain visible.
I tried several things, like filling the screen with spaces before an update, clearing the terminal buffer, etc, but it does not solve my issue.

It would be very kind of you if you could have a look at [my project](https://github.com/PascalLeMerrer/fileorganizer) and tell me what I'm doing wrong.

To reproduce the issue, just navigate in the folders whose content is displayed by the app.