data: add missing postal codes from monitor (#43)

Adds postal codes discovered by the PostalCode2NUTS monitor that are
either absent from TERCET data (404) or only have approximate matches.
NUTS estimates are derived from neighboring postal code lookups.

New entries: 1

Co-authored-by: OSMENDA Michal <michal.osmenda@ext.ec.europa.eu>

Author: bk86a

tercet_missing_codes.csv

@@ -2791,6 +2791,7 @@ LT,17138,LT011,LT01,LT0,high
 LT,17146,LT011,LT01,LT0,high
 LT,17169,LT011,LT01,LT0,high
 LT,17194,LT011,LT01,LT0,high
+LT,17238,LT011,LT01,LT0,medium
 LT,18103,LT011,LT01,LT0,high
 LT,18116,LT011,LT01,LT0,high
 LT,18120,LT011,LT01,LT0,high