hs: implement comments

[odanoburu]

because we want to read and print the data, it's better to allow comments only before the synset, as in:

# this is a valid comment
w: abandoned_ship # this is an invalid comment
# this is an invalid comment
w: derelict drf derelict 1
d: a ship abandoned on the high seas
e: we found an abandoned ship while diving
hyper: ship

# this is an invalid comment

# these are valid
# comments
w: abandoned_ship
# this is an invalid comment
w: derelict drf derelict 1
d: a ship abandoned on the high seas
e: we found an abandoned ship while diving
hyper: ship