gtksourceview3 has a nice bit of behavior called SMART_HOME_END_BEFORE, which makes the home key go to the start of the indentation on a line before going to the very beginning of the line. It was one of my favorite things about Scintilla, and I'm glad gtksourceview3 grabbed it.
This plugin enables that behavior in Gedit.
Put smarthome.plugin and smarthome.py in the ~/.local/share/gedit/plugins directory. You might have to create it first.