Actually, creating a new file at given directory would be a great feature. It is actually quite annoying to save any new file in a project with deep and complex directory structure (I look at you Java! ). Just hitting Ctrl+N and Ctrl+S opens the file save dialog in project base root. Many times, I'd just like to create a "sibling" for the file I currently work on. It would be very handy if it could be done directly.
It doesn't necessarily have to be in the sidebar though. Option in menu would be just fine, something like File > New in this directory... which would open the save dialog in the same directory as the currently active file.
Howdy, I have written a plugin in lua for this reason https://github.com/diazvictor/geany-plugins/tree/master/geany-advanced-new-file