Add a visual diff to split window

[bardo84]

Describe feature

Trilium has the cool split window feature.
A basic task is to compare two texts for completeness or differences.
Like
Textcompare or
Diffchecker
Even rudimentary diff would be already helpful.

Thanks for your work!

Additional Information

No response

[Aryankarma]

Hi, I would like to work on this feature. Can I take it on?

[meichthys]

Go for it, but do it on the new fork since this fork will not be accepting new features like this.

TriliumNext/Notes#84