DOCS-6963 : Improve security upgrade tutorial

* Split tutorial into four segments:
   * Deploy Replica Set Enforcing Access Control
   * Deploy Sharded Cluster Enforcing Access Control
   * Enforce Access Control in Existing Replica Set
   * Enforce Access Control in Existing Sharded Cluster

Author: ravindk89

config/htaccess.yaml

@@ -4690,6 +4690,13 @@ from: '/faq/mongo'
 to: '/mongo'
 type: 'redirect'
 code: 301
+outputs:
+  - 'after-v3.0'
+---
+from: '/core/enable-internal-authentication'
+to: '/core/enforce-keyfile-access-control-in-existing-replica-set'
+type: 'redirect'
+code: 301
 outputs:
   - 'after-v3.0'
 ...

source/core/security-internal-authentication.txt

@@ -90,6 +90,9 @@ see :doc:`/tutorial/upgrade-keyfile-to-x509`.
    .. toctree::
       :titlesonly:
 
-      /tutorial/enable-internal-authentication
+      /tutorial/enforce-keyfile-access-control-in-existing-replica-set
+      /tutorial/deploy-replica-set-with-keyfile-access-control
+      /tutorial/enforce-keyfile-access-control-in-existing-sharded-cluster
+      /tutorial/deploy-sharded-cluster-with-keyfile-access-control
       /tutorial/configure-x509-member-authentication
       /tutorial/upgrade-keyfile-to-x509