Add table of Contents in README.md

The table of Contents was added to README.md to improve the organization and navigation of the document. The new sections provide a comprehensive guide on the usage and installation of the ChatGPT integration for .NET. It also covers exceptions, modules, and API parameters.

README.md

@@ -2,7 +2,31 @@
 # ChatGPT integration for .NET
 [![Nuget](https://img.shields.io/nuget/v/OpenAI.ChatGPT.EntityFrameworkCore)](https://www.nuget.org/packages/OpenAI.ChatGPT.EntityFrameworkCore/)[![.NET](https://github.com/rodion-m/ChatGPT_API_dotnet/actions/workflows/dotnet.yml/badge.svg)](https://github.com/rodion-m/ChatGPT_API_dotnet/actions/workflows/dotnet.yml) \
 OpenAI Chat Completions API (ChatGPT) integration with DI and EF Core supporting. It allows you to use the API in your .NET applications. Also, the client supports streaming responses (like ChatGPT) via async streams.
-[NEW] `StructuredResponse` module allows you to get structured responses from the API as C# object. See: [StructuredResponse](#structuredresponse)
+
+[NEW!] `StructuredResponse` module allows you to get structured responses from the API as C# object. See: [StructuredResponse](#structuredresponse) section.
+
+## Content
+<!-- TOC -->
+* [ChatGPT integration for .NET](#chatgpt-integration-for-net)
+  * [Preparation](#preparation)
+  * [Installation](#installation)
+  * [Usage](#usage)
+  * [Exceptions](#exceptions)
+  * [Thread safety and async](#thread-safety-and-async)
+  * [Retries, timeouts and other policies](#retries-timeouts-and-other-policies)
+  * [Modules](#modules)
+    * [StructuredResponse](#structuredresponse)
+    * [Translator](#translator)
+  * [Examples](#examples)
+  * [API Parameters](#api-parameters)
+    * [Model](#model)
+    * [MaxTokens](#maxtokens)
+    * [Temperature](#temperature)
+* [Using raw client without DI](#using-raw-client-without-di)
+  * [Simple usage of the Chat Completions API (raw client)](#simple-usage-of-the-chat-completions-api-raw-client)
+  * [Streaming response with async streams (like ChatGPT)](#streaming-response-with-async-streams-like-chatgpt)
+  * [Continue dialog with ChatGPT (message history)](#continue-dialog-with-chatgpt-message-history)
+<!-- TOC -->
 
 ## Preparation
 First, you need to create an OpenAI account and get an API key. You can do this at https://platform.openai.com/account/api-keys.