Update README.md

Author: drmathias

README.md

@@ -6,4 +6,109 @@ A client for interacting with a Sia Skynet webportal.
 
 ## Usage
 
-View the [wiki](https://github.com/drmathias/csharp-skynet/wiki) for instructions on how to use the package.
+### Setup
+
+This library targets [.NET Standard 2.0](https://docs.microsoft.com/en-us/dotnet/standard/net-standard#net-implementation-support), so can be used across various platforms. The webportal client is a [typed client](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests#typed-clients), that uses `System.Net.Http.HttpClient` to make HTTP requests.
+
+```csharp
+using var httpClient = new HttpClient { BaseAddress = new Uri("https://siasky.net") };
+var skynetWebportal = new SkynetWebPortal(httpClient);
+```
+
+#### With Dependency Injection
+
+With `Microsoft.Extensions.DependencyInjection`, the client can easily be configured and set up to work with any Skynet webportal.
+
+```csharp
+public void ConfigureServices(IServiceCollection services)
+{
+    services.AddHttpClient<ISkynetWebPortal, SkynetWebPortal>(client =>
+    {
+        client.BaseAddress = new Uri("https://siasky.net");
+    });
+}
+```
+
+### Downloading Files
+
+Files can be downloaded from a Sia Skynet webportal, by providing a Skylink and optionally a path.
+
+```csharp
+try
+{
+    var skylink = Skylink.Parse("AABFphGLnADQbFx3tXOQdtjKf0MvFzqZoDIqj_VaebkqcA");
+    HttpContent response = await skynetWebportal.DownloadFile(skylink);
+}
+catch(HttpException e)
+{
+    // unsuccessful (non-2XX) response
+}
+```
+
+### Uploading Files
+
+This library uses `Microsoft.Extensions.FileProviders.Abstractions` (see [FileProviders](https://docs.microsoft.com/en-us/aspnet/core/fundamentals/file-providers)) which allows you to upload from many file providers. There are several methods available to simplify uploading single files, multiple files and directories.
+
+#### Upload a File
+
+```csharp
+try
+{
+    var file = new PhysicalFileInfo(new FileInfo("path/to/file.json"));
+    Skylink response = await skynetWebPortal.UploadFile(file);
+}
+catch(HttpException e)
+{
+    // unsuccessful (non-2XX) response
+}
+catch(HttpResponseException e)
+{
+    // invalid response from webportal
+}
+catch(IOException e)
+{
+    // file access errors
+}
+```
+
+#### Upload a Directory
+
+```csharp
+try
+{
+    var fileProvider = new PhysicalFileProvider("");
+    Skylink response = await skynetWebPortal.UploadDirectory(fileProvider, "directory/to/upload", recurse: true);
+}
+catch(DirectoryNotFoundException e)
+{
+    // invalid directory
+}
+catch(HttpException e)
+{
+    // unsuccessful (non-2XX) response
+}
+catch(HttpResponseException e)
+{
+    // invalid response from webportal
+}
+catch(IOException e)
+{
+    // file access errors
+}
+```
+
+#### Configuration
+
+By default, the Skynet path of an uploaded file is set to the file name. This behaviour can be changed, by specifying the Skynet path on an `UploadItem`.
+
+```csharp
+new UploadItem(file, "/images/sunset.jpg")
+// file will become available at https://siasky.net/{skylink}/images/sunset.jpg
+```
+
+For file uploads, the MIME type is automatically resolved based on the file extension. If you want to overwrite this behaviour, you can explicitly specify the MIME type on an `UploadItem`.
+
+```csharp
+new UploadItem(file, null, MediaTypeHeaderValue.Parse("image/gif"))
+// when downloaded, the Content-Type header will be set to image/gif
+```