chore: grammatical fixes

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: baywet

dotnet/src/Agents/OpenAI/Extensions/KernelContentExtensions.cs

@@ -6,7 +6,7 @@
 namespace Microsoft.SemanticKernel.Agents.OpenAI;
 
 /// <summary>
-/// Extensions methods for <see cref="KernelContent"/>.
+/// Extension methods for <see cref="KernelContent"/>.
 /// </summary>
 internal static class KernelContentExtensions
 {

dotnet/src/Experimental/Orchestration.Flow/Plugins/ReActEngine.gpt4.yaml

@@ -47,7 +47,7 @@ template: |
     If there is not a fitting function available to validate the result, I can provide the final answer in a clear and human-readable format.
     [END THOUGHT PROCESS]
 
-    IMPORTANT REMINDER: your each response should contain only one next step and only single one $JSON_BLOB. Do not provide more than one step.  
+    IMPORTANT REMINDER: each response should contain only one next step and only a single $JSON_BLOB. Do not provide more than one step.
     Let's break down the problem step by step and think about the best approach.
 
     Begin!

dotnet/src/InternalUtilities/planning/Schema/JsonSchemaResponse.cs

@@ -5,7 +5,7 @@
 namespace Microsoft.SemanticKernel;
 
 /// <summary>
-/// A class to describe the content schema of a response/return type from an KernelFunctionFactory, in a JSON Schema friendly way.
+/// A class to describe the content schema of a response/return type from a KernelFunctionFactory, in a JSON Schema friendly way.
 /// </summary>
 internal sealed class JsonSchemaResponse
 {