Add NixOS Support

[KanagawaMarcos]

If you try to run it on linux you are going to run into issues with missing Windows libraries

[kanagawamarcos@nixos:~/repos/Ocr/Console]$ dotnet run
Unhandled exception. System.TypeInitializationException: The type initializer for '<StartupCode$Engine>.$Library' threw an exception.
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.DllNotFoundException: Failed to find library "libleptonica-1.80.0.so" for platform x64.
   at InteropDotNet.LibraryLoader.LoadLibrary(String fileName, String platformName)
   at InteropRuntimeImplementer.LeptonicaApiSignaturesInstance.LeptonicaApiSignaturesImplementation..ctor(LibraryLoader loader)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.ConstructorInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr)
   --- End of inner exception stack trace ---
   at System.Reflection.ConstructorInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture)
   at InteropDotNet.InteropRuntimeImplementer.CreateInstance[T]()
   at Tesseract.Interop.LeptonicaApi.Initialize()
   at Tesseract.Interop.TessApi.Initialize()
   at Tesseract.Interop.TessApi.get_Native()
   at Tesseract.TesseractEngine..ctor(String datapath, String language, EngineMode engineMode, IEnumerable`1 configFiles, IDictionary`2 initialOptions, Boolean setOnlyNonDebugVariables)
   at Tesseract.TesseractEngine..ctor(String datapath, String language, EngineMode engineMode)
   at <StartupCode$Engine>.$Library..cctor() in /home/kanagawamarcos/repos/Ocr/Engine/Library.fs:line 10
   --- End of inner exception stack trace ---
   at Engine.Ocr.get_score()
   at Program.main(String[] args) in /home/kanagawamarcos/repos/Ocr/Console/Program.fs:line 7

To solve it one need to package the following libs to nix

libleptonica-dev
libtesseract-dev
libc6-dev
libjpeg62-turbo-dev
libgdiplus

libgdiplus already has a derivation