(DOCSP-46725): Added rolling index build conserations. (#677)

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- [DOCSP-46725](https://jira.mongodb.org/browse/46725)
-
[STAGING](https://deploy-preview-677--docs-ops-manager.netlify.app/data-explorer/indexes/#considerations)

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(cherry picked from commit 27085ea)

Author: corryroot

source/data-explorer/indexes.txt

@@ -28,6 +28,32 @@ by at least one of the following roles:
 
 - :authrole:`Project Data Access Admin`
 
+Considerations
+--------------
+
+By default, you can have up to three concurrent non-rolling index 
+builds. To learn more, see :manual:`Maximum Concurrent Index Builds
+</core/index-creation/#maximum-concurrent-index-builds>`.
+
+If you select to build indexes in a rolling fashion, you must ensure 
+the following:
+
+- Request rolling index builds and non-rolling index builds 
+  sequentially and not simultaneously. Wait for a currently executing 
+  index build to complete before you request another index 
+  build.
+
+- If you need to request multiple rolling index builds, wait for the 
+  currently executing rolling index build to complete before you 
+  request another rolling index build.
+
+To track rolling index builds, see the :ref:`Activity Feed 
+<activity-feed>`.
+
+For aborted rolling index builds, you must run :dbcommand:`listIndexes` 
+on each node to verify that the cancelled index no longer exists. 
+Otherwise, the cluster might remain in an inconsistent state.
+
 .. _de-view-indexes:
 
 View Indexes

source/tutorial/manage-alerts-and-events.txt

@@ -81,6 +81,8 @@ View All Activity
 
          .. include:: /includes/steps/project-activity.rst
 
+.. _activity-feed:
+
 Retrieve the Activity Feed
 --------------------------