[DOC-12426]: Feedback on Facets | Couchbase Docs

Added link to an explanation of index partitioning.

Author: RayOffiah

modules/fts/pages/fts-search-response-facets.adoc

@@ -8,8 +8,9 @@ In Facets, you already have a search in mind, and you want to collect additional
 
 Facet-query results may not equal the total number of documents across all buckets if: 
 
-1. There is more than one pindex. 
-2. Facets_size is less than the possible values for the field.
+1. There is more than one `pindex`; here, `pindex` refers to a search index partition.
+For more information, see xref:n1ql:n1ql-language-reference/index-partitioning.adoc[Index Partitioning].
+2. `Facets_size` is less than the possible values for the field.
 
 == Facets Results