Hits with documents containing all the query words

[curquiza]

Motivation

Currently, the search engine returns documents containing all the query words but also documents containing one of the query words.
The users might want to disable this behavior and only get documents containing all the query words only.
See meilisearch/meilisearch#1694.

Solution

A solution could be to add a optionalWords settings (or another name), set to true by default. The default behavior is to return documents containing all the query words but also documents containing one of the query words.
If set to false only the documents containing all the words of the query are returned.

Technical

This setting is already implemented on Milli's side, it just has to be exposed on MeiliSearch's side. The implementation of this feature should be quick.

[gmourier]

Thanks, @curquiza and @bnfd 😇

In the meantime, it is possible to have this behavior by wrapping each term with a phrase search expression.

e.g. "Hotel" "Champvert" will only return documents having the 2 terms Hotel and Champvert.

The limitation of the phrase search is that typographical errors are not taken into account.

[gmourier]

Locked in favor of #255