Enable in-page navigation by clicking links

After #296, the record detail view may include links to other records. Clicking those, however, leads to an entire new instance of the frontend being loaded. This shoud be easy to fix with [backbone-util](https://github.com/CentreForDigitalHumanities/backbone-util/blob/develop/doc/internal-links.md).

Start with the record detail view described in the issue and read backbone-util's internal-links documentation. Trace how links to other records are rendered and handled, then verify that clicking one updates the current frontend instance rather than loading a new one.

Written by the indexing model from the issue text.