improved msg-intro

rewritten the intro message for the freeplay
Signed-off-by: Rakasch <rakasch@abwesend.de>
grammer correction

changed "an" to "auf"
Signed-off-by: Rakasch <rakasch@abwesend.de>
changed "Kohle-Erz" to "Kohle"

since coal is not an ore.
Signed-off-by: Rakasch <rakasch@abwesend.de>