Display host availability

[klzig]

On about page:
Currently Available -or-
Not Currently Available - expected return 2020-08-02

Critical once #17 is implemented, since search can return unavailable hosts.

Alternative: Display Not Currently Available message as emptyText in Hosting page. Otherwise assume host is available (no need to say that). I think this is better than adding yet another entry to about.

Text from web site:
This member has marked themselves as not currently available for hosting, so their hosting information is not displayed.
Expected return 2036-03-17.

[klzig]

Should this replace complete hosting and contact info for host that was pinned when available? I don't think so.