Added upgrade index description & fixed a link's anchor

Author: rrelledge

content/operate/rs/installing-upgrading/upgrading/_index.md

@@ -5,7 +5,7 @@ categories:
 - docs
 - operate
 - rs
-description: null
+description: How to upgrade a cluster's Redis Software version, database version, and operating system.
 hideListLinks: true
 linkTitle: Upgrade
 weight: 60
@@ -21,7 +21,7 @@ To upgrade Redis Software:
 
 1. Upgrade the software on all nodes of the cluster using one of the following methods:
 
-    - [In-place upgrade]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-cluster/#in-place-upgrade">}}) - Directly upgrade Redis Software on each node in the cluster. Although this method is simpler than the rolling upgrade method, it might cause brief service interruptions as each node is upgraded.
+    - [In-place upgrade]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-cluster#in-place-upgrade">}}) - Directly upgrade Redis Software on each node in the cluster. Although this method is simpler than the rolling upgrade method, it might cause brief service interruptions as each node is upgraded.
 
     - [Rolling upgrade]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-cluster#rolling-upgrade">}}) - Minimize downtime by adding new nodes with an updated Redis Software version to the cluster, one at a time, while keeping the rest of the cluster operational. This method is recommended for production environments that require continuous availability.
 
@@ -37,6 +37,6 @@ To upgrade the cluster's operating system:
 
 2. Use one of the following rolling upgrade methods:
 
-    - [Extra node method]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-os#extra-node-upgrade">}}) - recommended if you have additional resources available
+    - [Extra node method]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-os#extra-node-upgrade">}}) - Recommended if you have additional resources available.
 
-    - [Replace node method]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-os#replace-node-upgrade">}}) - recommended if you cannot temporarily allocate additional resources
+    - [Replace node method]({{<relref "/operate/rs/installing-upgrading/upgrading/upgrade-os#replace-node-upgrade">}}) - Recommended if you cannot temporarily allocate additional resources.