Document cards export.

doc/modules.md

@@ -17,8 +17,26 @@ questionable.
 
 ### Members Info Printer
 
+Export Modules
+--------------
+
+These modules generate export files for other systems.
+
 ### Cards
 
+    (import cards)
+
+Exports files with card information for BrmDoor.
+
+    (cards-export mb cards desfire)
+
+* ```mb``` - mbase structure
+* ```cards``` - file path for generic cards
+* ```desfire``` - file path for desfire cards
+
+Generates two files with cards information for all active members. The
+file format is compatible with BrmDoor project.
+
 ### Web Static
 
     (import web-static)