The "fileedit-glob" setting:
The VALUE of this setting is a list of GLOB patterns matching files
which are allowed to be edited using the /fileedit page. An empty list
suppresses the feature. Example: *.md,*.txt The parsing rules are
complex; see https://fossil-scm.org/home/doc/trunk/www/globs.md#syntax
Note that /fileedit cannot edit binary files, so the list should not
contain any globs for, e.g., images or PDFs.