Multireddits need branding

[libertysoft3]

"X subreddits" https://saidit.net/me/m/allmusic

"a multireddit for X minutes" https://saidit.net/me/m/allmusic

"Add subreddit" https://saidit.net/me/m/allmusic

"PUBLIC MULTIREDDITS" https://saidit.net/user/d3rr

• add "multisub" and "multisubs" as new labels to config, use them, still translate them too
• get "sub" from config