Clarify voting weight decay and bsq staking

[m52go]

@huey735 does this address some of your points from #145? I know it doesn't cover everything, but I'm not sure we need the level of detail suggested there.

[huey735]

That's great @m52go. I also think that how the reputation is tracked is important here. Bisq contributors often move into new directories and bring along their fiat Account Age info. I imagine they'd like to do the same for their Reputation, when starting on a new directory.

[m52go]

@huey735 I clarified with Manfred that reputation cannot be transferred. It's tied to the wallet that issued the BSQ. I've added this information to both the user reference and user guide, so users are aware and can arrange accordingly.