In spite of there being considerable documentation sometimes in the
config file, we go with CC0 because we don't want the notion of
'derived work' of a config file.
The example `settings.conf` is also CC0. Add some docs to
it while we're at it.
- This enables working in three modes:
- No themes listed; all are shown without screenshots,
- Themes listed, showAll false; only those are shown,
- Themes listed, showAll true; the installed-but-not-listed
themes are shown after the listed ones, and have limited info.
- Although it's not necessarily accurate for an extensively-modified
Plasma configuration, we can read the Look-and-Feel from the
configuration files. Allows auto-detection.
- For OEM modes where there is already a theme, add a preselect:
key to pick a specific theme and have that one come up as already-
selected in the list.
- Don't re-run the lnftool if an already-selected theme is clicked
again. Use toggled() instead of clicked().
