Recommend#

Behavioural#

`PopularItemClauseBuilder`	popular_item \| Boost trendy items
`SubscribedCommunitiyClauseBuilder`	subscribed_communities \| Add communty filter queries for user's subscribed communities.
`UsersItemHistoryRecommender`	recommend_on_user_items \| Recommend items based on users item interaction history
`UserLastReadItem`	last_read \| Boost last read items.
`UserSearchHistoryRecommender`	recommend_on_searches \| Recommend items based on users search history

`SimilarItemsRecommender`	recommend_on_item \| Recommend other items based on provided item-id's
`RecencyBoost`	recency_boost \| Make recent documents more relevant