I could do that.
By the way, the tutorial for the -index command appears to have been regenerated from index.gmd as index.html so it is now (inadvertently) functioning as the directory page for the entire tutorial directory, masking the real index page. You see the problem from the main gmic.eu page. Choose Resources -> ScrIpting Tutorial and you are immediately in the tutorial for the -index command. I think you solved this issue the last time by the simple expedient of naming the tutorial page _index.html.
Edit: Seems simpler, in the long run, just to rename the tutorial file.
commit c7439d3cb64038e0506ce4ac01f5e9cbe759c3b0 (HEAD -> master, upstream/master, origin/master, origin/HEAD)
Author: Garry R. Osgood <grosgood@garryosgood.com>
Date: Tue Jun 8 07:14:08 2021 -0400
moved: valuesmanip/index.gmd -> valuesmanip/gindex.gmd
modified: Command_Guide.gmd
index.gmd->gindex.gmd: No content change, but the
tutorial file under the old name tended to generate
an 'index.html', which - unless special intervention
was done - would mask or overwrite the real tutorial
directory index file, making navigation difficult.
This change lays to rest the need for special intervention
Command_Guide.gmd: Updated valuesmanip/_index.html
2.9x series to valuesmanip/gindex.html.
note: Need to sync src/gmic_stdlib.gmic
8384: x "mv -f index.html _index.html" - obsolete? Not needed anymore
9982: #@cli : $$ https://gmic.eu/tutorial/_index.html -->
#@cli : $$ https://gmic.eu/tutorial/gindex.html
I think that checks all the boxes… Ah! The Technical Reference Guide: -index _index.html → gindex.html