* [Fix] add documentation regarding usage of filter/post_filter in k-NN plugin Signed-off-by: jiapinw <[email protected]> * Revise doc update based on comments and offline discussions Signed-off-by: jiapinw <[email protected]> * Update doc based on comments Signed-off-by: jiapinw <[email protected]> * Update _search-plugins/knn/filter-search-knn.md Co-authored-by: Nathan Bower <[email protected]> Signed-off-by: kolchfa-aws <[email protected]> --------- Signed-off-by: jiapinw <[email protected]> Signed-off-by: kolchfa-aws <[email protected]> Co-authored-by: kolchfa-aws <[email protected]> Co-authored-by: Nathan Bower <[email protected]>