Update the README.md with an example.

Author: Gonkers

README.md

@@ -1 +1,26 @@
-# ScryfallApi
+# Scryfall API Client
+## Getting Started
+Until I can get better documentation, see the [samples project](https://github.com/Gonkers/Scryfall-API-Client/tree/master/samples/ScryfallApi.WebSample) for examples.
+
+---
+## .NET Core Instructions
+### Add a service definition to your `startup.cs` file's `ConfigureServices` method.
+```c#
+services.AddHttpClient<ScryfallApiClient>(client =>
+{
+    client.BaseAddress = new Uri("https://api.scryfall.com/");
+});
+```
+### Add a `ScryfallApiClient` parameter and member to your Controller or Razor Page
+```c#
+ScryfallApiClient _scryfallApi { get; }
+
+public IndexModel(ScryfallApiClient scryfallApi)
+{
+    _scryfallApi = scryfallApi ?? throw new ArgumentNullException(nameof(scryfallApi));
+}
+```
+### Use the client
+```c#
+var randomCard = await _scryfallApi.Cards.GetRandom();
+```