H1406: jellyfish have no head

I did some research, and technically, a jellyfish does indeed have no head
(and, technically, no brain, just a "nerve net").  The part on top is a
"bell" used for buoyancy, not a head.

doc/fixes34.4

@@ -367,6 +367,7 @@ cutting a long worm in half would trigger segfault/accvio crash if the hit
 	took parent down to 1 hit point or if long worms had become extinct
 blinded invisible hero can't see self as invisible via ';' or '/'
 a hangup save while picking up gold from shop floor could duplicate that gold
+jellyfish do not technically have a head
 
 
 Platform- and/or Interface-Specific Fixes