(Doc+) Clarify dimension field requirements for time_series aggregation (#119442) (#121162)

docs/reference/aggregations/bucket/time-series-aggregation.asciidoc

@@ -6,9 +6,14 @@
 
 preview::[]
 
-The time series aggregation queries data created using a time series index. This is typically data such as metrics
+The time series aggregation queries data created using a <<tsds,Time series data stream (TSDS)>>. This is typically data such as metrics
 or other data streams with a time component, and requires creating an index using the time series mode.
 
+[NOTE]
+====
+Refer to the <<differences-from-regular-data-stream, TSDS documentation>> to learn more about the key differences from regular data streams.
+====
+
 //////////////////////////
 
 Creating a time series mapping