Update airweed data

DEV_GROUPS.md

@@ -123,6 +123,8 @@ This is the list of all groups used for nodes. Note: If no number/rating is spec
 * `fern`: Fern
 * `flower`: Flower
 * `seagrass`: Seagrass
+* `airweed`: Airweed
+* `airweed_insert`: Airweed that is 'inert' (i.e. bubbles are not ready)
 * `alga`: Alga
 * `clam`: Clam
 

mods/mobs/mob_npc.lua

@@ -401,7 +401,7 @@ for _, npc_type_table in pairs(npc_types) do
                           end
                       elseif iname == "rp_default:reed_block" then
                           say(S("Did you try to dry it in the furnace?"), name)
-                      elseif iname == "rp_default:airweed" then
+                      elseif minetest.get_item_group(iname, "airweed") > 0 then
                           if npc_type == "carpenter" then
                              say(S("Airweed is an underwater plant with little capsules filled with air. Use it underwater to release air bubbles and catch some breath."), name)
                           elseif npc_type == "butcher" then