hud

hud.add_toggle(spec)

Put a toggle of this mod's own into the player's control bar, where it can be reordered and hidden like the built-in ones

spec

table

{ id = "...", label = "..."?, glyph = "X"?, on_click = function() end, is_on = function() return bool end? }

returns boolean False when the table is missing an id or an on_click