voices: pinned or boosted posts for certain users

[jessewashburn]

Going off what was mentioned at today's meeting, we could add a way for community leaders' or special users' voices to be pinned at the top in order to boost the visibility of what they post. Could be done by user or by post and have it pin forever or for a selected amount of time.

Alternatively, having a separate voices section above the current one for important posts.