Detail for specified facet term

`facet_id`: "topics", "facility", "format", "genre", or "rights".
`term_id`: A term ID from one of the following lists:

- http://partner.densho.org/vocab/api/0.2/topics.json
- http://partner.densho.org/vocab/api/0.2/facility.json
- http://partner.densho.org/vocab/api/0.2/format.json
- http://partner.densho.org/vocab/api/0.2/genre.json
- http://partner.densho.org/vocab/api/0.2/rights.json

GET /api/0.2/facet/topics/264/?format=api