verify slide mode UX

[nkh]

Add the possibility to run user script with shortcuts

reserve a leader shortcut

keys in that mode are set by an eternal setup

it's possible to load a setup for the user script manually, programmatically, and via an option

example shortcuts

• insert a set of graph node
• create a git diagram
• insert nodes a to z

[nkh]

fixed in 3cd9e7f