Optimize readme (#262)

* Migrate source and example directories to lowercase

Renamed all 'Src' and 'Examples' directories to 'src' and 'examples' for consistency and to follow common directory naming conventions. Updated GitHub Actions workflows to use the new lowercase paths and upgraded actions/checkout and actions/setup-dotnet to v5.

* Update SmtpServer.sln

* Fix project reference paths to use lowercase 'src'

Updated project reference paths in SampleApp and WorkerService csproj files to use 'src' instead of 'Src' for consistency and to avoid case sensitivity issues on some file systems.

* Update README and project description for clarity

Improved the README with clearer language, better formatting, and added installation instructions. Enhanced the project description in the .csproj file to better reflect the features and capabilities of the SMTP server.

Author: tinohager

README.md

@@ -2,27 +2,33 @@
 
 [![NuGet](https://img.shields.io/nuget/v/SmtpServer.svg)](https://www.nuget.org/packages/SmtpServer/)
 
-SmtpServer is a simple, but highly functional SMTP server implementation. Written entirely in C# it takes full advantage of the .NET TPL to achieve maximum performance.
+**SmtpServer** is a lightweight yet powerful SMTP server implementation in C#.  
+Built entirely in .NET, it leverages the Task Parallel Library (TPL) for maximum performance.
 
-SmtpServer is available via [NuGet](https://www.nuget.org/packages/SmtpServer/)
-
-# Whats New?
+## 🆕 What's New?
 
 Check the [Changelog](https://github.com/cosullivan/SmtpServer/blob/master/CHANGELOG.md)
 
-# What does it support?
+## ⚡ Supported ESMTP Extensions
 
-SmtpServer currently supports the following ESMTP extensions:
+SmtpServer currently supports the following extensions:
 
 - STARTTLS
 - SIZE
 - PIPELINING
 - 8BITMIME
 - AUTH PLAIN LOGIN
 
-# How can it be used?
+## Installation
+
+The package is available on [NuGet](https://www.nuget.org/packages/SmtpServer)
+```powershell
+PM> install-package SmtpServer
+```
+
+## 🚀 Getting Started
 
-At its most basic, it only takes a few lines of code for the server to be listening to incoming requests.
+Starting a basic SMTP server requires only a few lines of code:
 
 ```cs
 var options = new SmtpServerOptionsBuilder()
@@ -34,7 +40,7 @@ var smtpServer = new SmtpServer.SmtpServer(options, ServiceProvider.Default);
 await smtpServer.StartAsync(CancellationToken.None);
 ```
 
-# What hooks are provided?
+### What hooks are provided?
 
 There are three hooks that can be implemented; IMessageStore, IMailboxFilter, and IUserAuthenticator.
 

src/SmtpServer/SmtpServer.csproj

@@ -6,7 +6,7 @@
     <AssemblyName>SmtpServer</AssemblyName>
     <RootNamespace>SmtpServer</RootNamespace>
     <Version>10.0.1</Version>
-    <Description>.NET SmtpServer</Description>
+    <Description>High-performance, flexible SMTP server implementation for .NET with support for ESMTP, TLS, authentication, and custom message handling.</Description>
     <Authors>Cain O'Sullivan</Authors>
     <Copyright>2015-2023</Copyright>
     <RepositoryUrl>https://github.com/cosullivan/SmtpServer</RepositoryUrl>