add datastream support, refactor custom completion (#32)

pkg/es/index.go

@@ -59,6 +59,12 @@ func filterIndices(conf *cfg.Config, list indices.Response) indices.Response {
 		if !conf.Partials && strings.HasPrefix(*index.Index, "partial-") {
 			continue
 		}
+
+		if strings.HasPrefix(*index.Index, ".ds-") {
+			// ignore data stream backing indicies
+			continue
+		}
+
 		selectedlist = append(selectedlist, index)
 	}