main_start/end support for multiboxes (#1246)

* `main_start`/`end` support for multiboxes

* this is why im making a pr and not merging without looking

Author: nh6574

lovely/multi_box_descriptions.toml

@@ -73,6 +73,8 @@ local multi_boxes = {}
 if AUT.multi_box then
     for i, box in ipairs(AUT.multi_box) do
         box.background_colour = box.background_colour or AUT.box_colours and AUT.box_colours[i+1] or nil
+        if AUT.box_starts and AUT.box_starts[i] then table.insert(box, 1, AUT.box_starts[i]) end
+        if AUT.box_ends and AUT.box_ends[i] then table.insert(box, AUT.box_ends[i]) end
         multi_boxes[#multi_boxes+1] = desc_from_rows(box)
     end
 end

src/game_object.lua

@@ -1222,6 +1222,10 @@ Set `prefix_config.key = false` on your object instead.]]):format(obj.key), obj.
                 target.set = res.set or target.set
                 target.scale = res.scale
                 target.text_colour = res.text_colour
+                if desc_nodes == full_UI_table.main then
+                    full_UI_table.box_starts = res.box_starts
+                    full_UI_table.box_ends = res.box_ends
+                end
             end
 
             if desc_nodes == full_UI_table.main and not full_UI_table.name then
@@ -3000,6 +3004,10 @@ Set `prefix_config.key = false` on your object instead.]]):format(obj.key), obj.
                 target.set = res.set or target.set
                 target.scale = res.scale
                 target.text_colour = res.text_colour
+                if desc_nodes == full_UI_table.main then
+                    full_UI_table.box_starts = res.box_starts
+                    full_UI_table.box_ends = res.box_ends
+                end
             end
             if desc_nodes == full_UI_table.main and not full_UI_table.name then
                 full_UI_table.name = localize { type = 'name', set = target.set, key = res.name_key or target.key, nodes = full_UI_table.name, vars = res.name_vars or res.vars or {} }