added full text search for dendrite

roles/custom/matrix-dendrite/defaults/main.yml

@@ -211,3 +211,6 @@ matrix_dendrite_userapi_auto_join_rooms: []
 # statistics reporting configuration. These statistics contain the server
 # name, number of active users and some information on your deployment config.
 matrix_dendrite_report_stats: false
+
+# Configuration for the full-text search engine.
+matrix_dendrite_syncapi_search_enabled: false

roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2

@@ -355,7 +355,7 @@ sync_api:
   # Configuration for the full-text search engine.
   search:
     # Whether or not search is enabled.
-    enabled: false
+    enabled: {{ matrix_dendrite_syncapi_search_enabled }}
     # The path where the search index will be created in.
     index_path: "/matrix-media-store-parent/searchindex"
     # The language most likely to be used on the server - used when indexing, to