docs: remade README.md entirely

Author: DennisDyallo

README.md

@@ -1,4 +1,4 @@
-<!-- Copyright 2021 Yubico AB
+<!-- Copyright 2024 Yubico AB
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -21,29 +21,50 @@ limitations under the License. -->
 
 # .NET YubiKey SDK
 
-This is a cross-platform, all encompassing SDK for the YubiKey aimed at large to mid-sized enterprise
-customers. This version is written against .NET Core, and will eventually include bindings to languages
-outside the direct .NET ecosystem.
+Enterprise-grade cross-platform SDK for YubiKey integration, built on .NET.
+
+## Table of Contents
+- [Quick Start](#quick-start)
+- [Documentation](#documentation)
+- [SDK Support](#sdk-support)
+- [SDK Packages](#sdk-packages)
+- [Project Structure](#project-structure)
+- [Contributing](#contributing)
+- [Security](#security)
 
 ## Quick Start
-```csharp
-// Installation
+
+### Installation
+```bash
 dotnet add package Yubico.YubiKey
 ```
 
+### Basic Usage
+```csharp
+using Yubico.YubiKey;
+
+// Chooses the first YubiKey found on the computer.
+IYubiKeyDevice? SampleChooseYubiKey()
+{
+    IEnumerable<IYubiKeyDevice> list = YubiKeyDevice.FindAll();
+    return list.First();
+}
+```
+
 ## Documentation
 
-The public documentation for this project is located
-at [https://docs.yubico.com/yesdk/](https://docs.yubico.com/yesdk/).  
-Here you can find both API reference and a user's manual that describes the concepts that this SDK exposes.
+📚 Official documentation: [docs.yubico.com/yesdk](https://docs.yubico.com/yesdk/)
+- User Manual
+- API Reference
 
 ## SDK Support
-The SDK is targeting net47, netstandard2.0 and netstandard2.1.  
-This means the SDK can be loaded in NET Framework, NET6 and upwards.
 
-## SDK Packages
+Supported Target Frameworks:
+- .NET Framework 4.7
+- .NET Standard 2.1
+- .NET 6 and above
 
-The SDK consists of the following assemblies:
+## SDK Packages
 
 ### Public Assemblies
 
@@ -55,44 +76,48 @@ Platform abstraction layer (PAL) providing:
 - OS-specific functionality abstraction
 - Device enumeration
 - Utility classes for various encoding/decoding operations:
-    - Base32
-    - Tag-Length-Value (BER TLV)
-    - ModHex
+  - Base16
+  - Base32
+  - Tag-Length-Value (BER Encoded TLV)
+  - ModHex
 
 ### Internal Assemblies
 
 #### Yubico.DotNetPolyfills
 > ⚠️ **Not for public use**  
-> Backports BCL features needed by the SDK. Target newer .NET versions directly if you need modern features.
+> Backports BCL features needed by the SDK.
 
 #### Yubico.NativeShims
 > ⚠️ **Not for public use**  
-> 🔧 **Unmanaged Library** 
+> 🔧 **Unmanaged Library**  
 > Provides stable ABI for P/Invoke operations in Yubico.Core.
 
-## Project structure
-
-The root of this repository contains the various projects that make up the SDK. Inside each project
-folder, you will find:
+## Project Structure
 
-- docs - Supplementary documentation content for the SDK's API documentation.
-- examples - Example code demonstrating various capabilities of the SDK.
-- src - All source code that makes up the project.
-- tests - Unit and integration tests for the project.
+Repository organization:
+- 📁 `docs/` - API documentation and supplementary content
+- 📁 `examples/` - Sample code and demonstrations
+- 📁 `src/` - Source code for all projects
+- 📁 `tests/` - Unit and integration tests
 
 ## Contributing
 
-Please read the [Contributor's Guide](./CONTRIBUTING.md) and [Getting started](./contributordocs/getting-started.md)
-pages before opening a pull request on this project.
+1. Read the [Contributor's Guide](./CONTRIBUTING.md)
+2. Review [Getting Started](./contributordocs/getting-started.md)
+3. Submit your Pull Request
+
+### Building the Project
+
+Prerequisites:
+1. Install required tools (see [Getting Started](./contributordocs/getting-started.md))
+2. Load `Yubico.NET.SDK.sln` into your IDE.
+3. Build solution
+
 
-### Building
+## Security
 
-Read the [Getting started](./contributordocs/getting-started.md) page to understand the prerequisites needed
-to build. Once those have been installed, you should be able to load the Yubico.NET.SDK.sln file and build.
+For security concerns, please see our [Security Policy](./SECURITY.md).
 
-Note that it is also possible to build the DocFX output at the same time as building the libraries. However,
-that is not done by default.
+---
 
-If you want to build the DocFX output when you build the libraries using Visual Studio, open the Visual
-Studio solution file, and open `Build:Configuration Manager...`. In the resulting window, under
-`Active solution configuration:` is a drop-down menu. Select `ReleaseWithDocs`.
+📫 Need help? [Create an issue](https://github.com/Yubico/Yubico.NET.SDK/issues/new/choose)