System Information
Operating system: Linux
Graphics card: Intel
Blender Version
Broken: 2.92
Worked: N/A
Short description of error
There doesn't seem to be much way to add a new "Group Input" or "Group Output" node in the "Geometry Node Editor" if you delete the ones you start with.
Exact steps for others to reproduce the error
Create a geometry node tree and delete its starting nodes from the "Geometry Node Editor".