Update README.md

Author: yakovypg

README.md

@@ -1,2 +1,157 @@
 # NetArgumentParser
-Parser for command-line options and arguments.
+**NetArgumentParser** is a cross-platform, free and open source library for parsing command-line options and arguments.
+
+## Table of contents
+*    [Main Features](#main-features)
+*    [Quick Start](#quick-start)
+     *    [Build Project](#build-project)
+     *    [Test Project](#test-project)
+     *    [Connect Project](#connect-project)
+     *    [Step-By-Step Connection](#step-by-step-connection)
+*    [Project Status And TODO List](#project-status-and-todo-list)
+*    [Development](#development)
+*    [Contributing](#contributing)
+*    [License](#license)
+
+## Main Features
+This library supports the following main features:
+- Parse options starting with a minus (such as `-v`).
+- Parse options starting with a double minus (such as `--version`).
+- Parse options starting with a slash (such as `/v` or `/version`).
+- Parse compound options (such as `-lah`).
+- Parse long name options starting with a minus (such as `-version`).
+- Extract extra arguments.
+- Support custom converters.
+- Configure command-line help generation.
+
+## Quick Start
+To start working with the library you need to build it and then connect it to your project.
+
+### Build Project
+You can [build](https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-build) the library with the following command, which should be run from the root of the library.
+```
+dotnet build
+```
+
+### Test Project
+You can [test](https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-test) the library with the following command, which should be run from the root of the library.
+```
+dotnet test
+```
+
+### Connect Project
+At fitst, you need to [add reference](https://learn.microsoft.com/en-us/dotnet/core/tools/dotnet-add-reference) to the library:
+```
+dotnet add reference /Path/To/Lib/Core/NetArgumentParser
+```
+
+Next, you need to add the usings you need:
+```cs
+using NetArgumentParser;
+using NetArgumentParser.Converters;
+using NetArgumentParser.Generators;
+using NetArgumentParser.Options;
+using NetArgumentParser.Options.Context;
+```
+
+Finally, you can work with the parser.
+
+### Step-By-Step Connection
+Let's consider this step-by-step instructions for creating a sample project and connecting this library to it.
+- Step 1: Go to the directory with your projects.
+```
+cd ~/Repos
+```
+- Step 2: Create folder for your project and go to it.
+```
+mkdir MyProject && cd MyProject
+```
+- Step 3: Create solution.
+```
+dotnet new sln
+```
+- Step 4: Create your project.
+```
+dotnet new console -o MyProject
+```
+- Step 5: Add your project to the solution.
+```
+dotnet sln add ./MyProject
+```
+- Step 6: Add folder for external projects and go to it.
+```
+mkdir Vendor && cd Vendor
+```
+- Step 7: Clone **NetArgumentParser** repository.
+```
+git clone https://github.com/yakovypg/NetArgumentParser.git
+```
+- Step 8: Go back to the root folder.
+```
+cd ..
+```
+- Step 9: Add **NetArgumentParser** to the solution. 
+```
+dotnet sln add Vendor/NetArgumentParser/Core/NetArgumentParser
+```
+- Step 10: Go to your project folder.
+```
+cd MyProject
+```
+- Step 11: Add reference to the **NetArgumentParser**.
+```
+dotnet add reference ../Vendor/NetArgumentParser/Core/NetArgumentParser
+```
+- Step 12: Open Program.cs file and try using the **NetArgumentParser**.
+```cs
+using System;
+using System.Collections.Generic;
+using NetArgumentParser;
+using NetArgumentParser.Options;
+
+int? angle = default;
+
+var option = new ValueOption<int>("angle", "a",
+    description: "angle by which you want to rotate the image",
+    afterValueParsingAction: t => angle = t);
+
+var parser = new ArgumentParser();
+parser.AddOptions(option);
+parser.ParseKnownArguments(args, out List<string> extraArguments);
+
+Console.WriteLine($"Angle: {angle}");
+Console.WriteLine($"Extra arguments: {string.Join(' ', extraArguments)}");
+```
+- Step 13: Build the project.
+```
+dotnet build -c Release
+```
+- Step 14: Run the created application.
+```
+dotnet run --angle 45 A
+```
+
+## Project Status And TODO List
+**NetArgumentParser** is currently under development. There are some features that need to be added to the project:
+- Add support of subcommands.
+- Add counter option.
+- Add support of custom option prefix characters.
+- Add support of custom assignment characters.
+- Add support of reflection-based configuring option set using special attributes.
+- Add support of restricting the set of values for an argument.
+- Add support of hidden arguments and aliases.
+- Add support of import and export JSON configuration.
+- Add support of parent parsers.
+- Add NuGet package.
+
+## Documentation
+You can find documentation in the [Docs](Docs) folder. 
+
+## Development
+The project is developed on the .NET 8.0 platform. To continue development you will need the .NET SDK and .NET Runtime of the appropriate version.
+
+## Contributing
+Contributions are welcome, have a look at the [CONTRIBUTING.md](CONTRIBUTING.md) document for more information.
+
+## License
+The project is available under the [GPL-3.0](LICENSE) license.