Add user guide to demonstrate not well known features

[xdelaruelle]

Aside from module load and module list, Environment Modules is offering numerous possibilities that are mostly unknown. It would be interesting to have in the documentation a user guide that demonstrate all these unknown features.

First list of features to cover in such user guide:

• -o
• -d/-L
• no_indepth
• --json
• source-sh (avec spack)
• sh-to-mod/mod-to-sh
• module edit
• module-virtual: use one file for every versions
• logging
• hide/forbid/tag
• adv vers spec: filter available versions
  • syntax like Spack
• dependencies requirement & conflict
  • cannot load if another loaded module express a conflict
  • --force things
• hook (find a use case to demonstrate that)
• perf? (cache, source_cache, massive load work)
• collections
• stash
• lint
• debug with --timer, -D, -DD
• module append-path/prepend-path/is-avail/is-loaded/etc
• envml
• mogui?
• protected_envvar

Along with the guide, the modulefiles used in the examples should also be recorded in the repository, for users to be able to try on their side these examples.

All of this content will be shown for the first time at HPSFcon 2026.