(DOCSP-33794) Adds data lake pipeline limit (#5154) (#5176)

Author: sarahsimpers

source/reference/limits.txt

@@ -358,6 +358,10 @@ limits:
    * - Unique shard keys per {+atlas+} project
      - 40
 
+   * - `Atlas Data Lake <https://www.mongodb.com/docs/datalake/>`__
+       pipelines per {+atlas+} project
+     - 25
+
 {+atlas+} Label Limits
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