display/hide an HTML block using an accordion and 'read more' button
syntax: {up readmore=text button | textless=fold} hidden content {/up readmore}
🟩 upbtn-makefile PREFS.INI :
changelog : textmore=Voir les nouveautés
| textmore-class=bd-primary bd-arrondi ph1
| class=tr
| panel-style=box bg-beige p1 m-child-raz