added documentation for mongodb atlas database secrets engine eventua…

changelog/24152.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+website/docs: Add note about eventual consietency with the MongoDB Atlas database secrets engine
+```

website/content/docs/secrets/databases/mongodbatlas.mdx

@@ -84,6 +84,16 @@ the proper permissions, it can generate credentials.
         username           v-my-password-role-DKbQEg6uRn
     ```
 
+    Each invocation of the command generates a new credential.
+
+    MongoDB Atlas database credentials eventually become consistent when the
+    [MongoDB Atlas Admin API](https://www.mongodb.com/docs/atlas/reference/api-resources-spec/v2/)
+    coordinates with hosted clusters in your Atlas project. You cannot use the
+    credentials successfully until the consistency process completes.
+
+    If you plan to use MongoDB Atlas credentials in a pipeline, you may need to add
+    a time delay or secondary process to account for the time required to establish consistency.
+
 #### Client certificate credentials
 
 1.  Configure a role that maps a name in Vault to a MongoDB Atlas command that executes and