dired help and development status

Hi,

I could not find an users mailing list so I will ask here. In dired I
can navigate the tree and see a preview of the file on the right pane.
How can I edit the file whose preview I see? I tried some of the ways
this works in emacs without success.

On another subject, I got a bunch of compiler warnings when building
qemacs and while using dired qemacs hang. The last change in this repo
(nongnu.org) was in 2020. I wonder if development has stopped or if it
has moved to some other repo? I found a bunch of qemacs clones in
github but none that seems the successor to this one.