Proposal for feature contribution: Emacs live pdf preview

Hey there,

this is my first time contacting a FOSS project so please forgive me 
(and tell me) if i'm missing some protocol here. I've been using 
LilyPond for a few years now, absolutely love it and have recently 
started using it in Emacs instead of Frescobaldi. But one thing i'm 
still missing is the live compile-preview-update feature of frescobaldi: 
Whenever i save the changes to my *.ly file, the file is automatically 
compiled and the integrated pdf preview is updated.

I could not find this feature in the officially provided lilypond-mode 
for Emacs and thus, i implemented it on my own. Would you be interested 
in me creating a pull request to the official GitLab repo in order to 
integrate this as an optional feature (e.g. a minor mode; analogous to 
[latex-preview-pane](https://github.com/jsinglet/latex-preview-pane))?

I am looking forward to your reply, best regards
Max Hagspiel