Improved the docs for the RedisCacheOptions.InstanceName property (#44711)

src/Caching/StackExchangeRedis/src/RedisCacheOptions.cs

@@ -31,7 +31,8 @@ public class RedisCacheOptions : IOptions<RedisCacheOptions>
     public Func<Task<IConnectionMultiplexer>>? ConnectionMultiplexerFactory { get; set; }
 
     /// <summary>
-    /// The Redis instance name.
+    /// The Redis instance name. Allows partitioning a single backend cache for use with multiple apps/services.
+    /// If set, the cache keys are prefixed with this value.
     /// </summary>
     public string? InstanceName { get; set; }