mention container capacity ref #2

docs/web/docs/Specification/Containers.md

@@ -55,7 +55,7 @@ elements of plan definitions.
 | containerStop | string | valid container stop ids  | \-      | id of the destination stop (allows to omit *to*)       |
 | arrivalPos    |float(m)|                           | \-1     | arrival position on the destination edge               |
 
-The vehicle to use has to exist already and the route to take is defined by the vehicle. The container is loaded into the vehicle if it stops on the 'from' edge and any of the following conditions are met
+The vehicle to use has to exist already and the route to take is defined by the vehicle. The vehicle needs to have capacity to transport additional containers (see [vType attribute containerCapacity](../Definition_of_Vehicles,_Vehicle_Types,_and_Routes.md#available_vtype_attributes)). The container is loaded into the vehicle if it stops on the 'from' edge and any of the following conditions are met
 
 - the 'line' attribute of the vehicle or the 'id' of the vehicle is given in the list defined by the 'lines' attribute of the `transport` OR the lines attribute contains 'ANY' and the vehicle stops at the destination 'containerStop' of the `transport` (or at the destination edge if no destination containerStop is defined).
 - the vehicle has a triggered stop and the container position is within the range of startpos,endPos of the stop.