Display letter summary in search results

[svandaalen]

Request from Nina:

Ik zou daaronder ook graag hebben dat de summary in Engels zichtbaar is, dan kunnen mensen eventueel meteen zien of deze brief nuttig is voor hen (dat stond ook in onze wensenlijst, maar dat hebben we bij vorig overleg niet meer besproken, zie https://edition-humboldt.de/briefe/index.xql?l=en waar ze begin van de brief geven, maar lijkt me ideaal voor de samenvatting).

[svandaalen]

This also requires some work on the side of Broccoli. In any way, shape, or form the summaries have to be added to the Elastic index so that TAV can display the summaries in the search hits. Are we going to add them as type text? Where does Broccoli get the summaries from? The summaries sit in body.metadata.summary of a tf:File annotation.

[hayco]

Next step forward is to add body.metadata.summary to the index. This will cause ES to index the summary field and makes it 'findable'. It will also add summary to search results passed by 🥦.

[hayco]

The Suriano index used in TAV now contains a summary field.

This leaves TAV to show the summary field for now.

[hayco]

Highlighting search terms in index fields requires some changes in 🥦 -> knaw-huc/broccoli#50

[svandaalen]

This functionality has been added in TAV in f6b6453.