also ask user to add <x> many blocks to master turtle

src/main.lua

@@ -918,6 +918,11 @@ while true do
                     dimensions=dimensions
                 }, "HB_vprint_pairacknowledge")
             end
+
+            print("This turtle needs "..tostring(VP_calccost(stacks["stacks"][i], stacks["height"],dimensions["x"],dimensions["z"])).." blocks.")
+            print("Please ensure that turtle has that many blocks and press enter to continue.")
+            read("")
+
             local x,y = 0,0
             for _,v in pairs(accepted) do
                 x,y = VP_selectpos(buf,dimensions,"Select position of turtle "..tostring(v), x,y)