add some more documentation about used ports (#161)

also add more ports to docker-compose.yml

Signed-off-by: Felix Bartels <felix@host-consultants.de>

docker-compose.yml

@@ -368,6 +368,7 @@ services:
     depends_on:
       - kopano_server
     ports:
+      - "${POP3PORT:-110}:110"
       - "${IMAPPORT:-143}:143"
     volumes:
       - kopanossl/:/kopano/ssl
@@ -386,6 +387,8 @@ services:
     image: ${docker_repo:-zokradonh}/kopano_core:${CORE_VERSION:-latest}
     depends_on:
       - kopano_server
+    ports:
+      - "${ICALPORT:-8080}:8080"
     volumes:
       - kopanossl/:/kopano/ssl
       - kopanosocket/:/run/kopano