Updated service comments

Author: seesharprun

src/Services/CosmosDbService.cs

@@ -18,7 +18,7 @@ public class CosmosDbService
     /// <param name="endpoint">Endpoint URI.</param>
     /// <param name="databaseName">Name of the database to access.</param>
     /// <param name="containerName">Name of the container to access.</param>
-    /// <exception cref="ArgumentNullException">Thrown when endpoint, key, databaseName, or containerName is either null or empty.</exception>
+    /// <exception cref="ArgumentNullException">Thrown when endpoint, databaseName, or containerName is either null or empty.</exception>
     /// <remarks>
     /// This constructor will validate credentials and create a service client instance.
     /// </remarks>

src/Services/OpenAiService.cs

@@ -32,7 +32,7 @@ Summarize this prompt in one or two words to use as a label in a button on a web
     /// </summary>
     /// <param name="endpoint">Endpoint URI.</param>
     /// <param name="modelName">Name of the deployed Azure OpenAI model.</param>
-    /// <exception cref="ArgumentNullException">Thrown when endpoint, key, or modelName is either null or empty.</exception>
+    /// <exception cref="ArgumentNullException">Thrown when endpoint, or modelName is either null or empty.</exception>
     /// <remarks>
     /// This constructor will validate credentials and create a HTTP client instance.
     /// </remarks>