Add AREAs to overview table in documentation

Add a new column "AREA" to the table EcmrConsignment in chapter 5 of the documentation. The corresponding AREAs must then be entered in the table.

Here is a link to the table: https://git.openlogisticsfoundation.org/wg-electronictransportdocuments/ecmr/ecmr-model/-/blob/main/documentation/05_building_block_view.adoc?ref_type=heads#user-content-ecmrconsignment