Text Editor: Duplicate Row Below
Many Text Editors have the very popular functionality of "duplicate the current row below it", saving the users lots of time of selecting, copying, pasting.
Shortcut keys are usually: Shift+Ctrl+d or Alt+Ctrl+d.
It would be a great productivity boost, if the Gnome Text Editor would add this feature.
Related: GNOME/gnome-text-editor#478 (closed)