[DOCS] Minor data stream docs fixes

docs/reference/data-streams/data-streams.asciidoc

@@ -27,12 +27,9 @@ backing indices.
 
 image::images/data-streams/data-streams-diagram.svg[align="center"]
 
-To configure its backing indices, each data stream requires a matching
-<<indices-templates,index template>>. This template contains:
-
-* An index pattern matching the stream's name.
-
-* Mappings and settings for the stream's backing indices.
+Each data stream requires a matching <<indices-templates,index template>>. The
+template contains the mappings and settings used to configure the stream's
+backing indices.
 
 Every document indexed to a data stream must contain a `@timestamp` field,
 mapped as a <<date,`date`>> or <<date_nanos,`date_nanos`>> field type. If the

docs/reference/indices/get-data-stream.asciidoc

@@ -134,8 +134,7 @@ Universally unique identifier (UUID) for the index.
 `generation`::
 (integer)
 Current <<data-streams-generation,generation>> for the data stream. This number
-acts as a cumulative count of the stream's backing indices, including
-deleted indices.
+acts as a cumulative count of the stream's rollovers, starting at `1`.
 
 `status`::
 (string)