Add additional behavior to .here

[Niewidzialny84]

.here was used in 1.0 with text following command.
In 2.0 there is already implemantation for it, but additionally there could be added slash command /here <text> serving the same purpose.
New command should also be allowed to use without additional parameters only mentioning users.

Also nice would be to change bahaviour of command on non-whitelisted chanels where currently is printed information about channel not whitelisted to simply call discord @here