Adding Initial API support, updating readme

Geekbot.net/Commands/Cat.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Discord.Commands;
+using Newtonsoft.Json;
+
+namespace Geekbot.net.Commands
+{
+    public class Cat : ModuleBase
+    {
+        [Command("cat", RunMode = RunMode.Async)]
+        [Summary("Return a random image of a cat.")]
+        public async Task Say()
+        {
+            using (var client = new HttpClient())
+            {
+                try
+                {
+                    client.BaseAddress = new Uri("http://random.cat");
+                    var response = await client.GetAsync("/meow.php");
+                    response.EnsureSuccessStatusCode();
+
+                    var stringResponse = await response.Content.ReadAsStringAsync();
+                    var catFile = JsonConvert.DeserializeObject<CatResponse>(stringResponse);
+                    await ReplyAsync(catFile.file);
+                }
+                catch (HttpRequestException e)
+                {
+                    await ReplyAsync($"Seems like the dog cought the cat (error occured)\r\n{e.Message}");
+                }
+            }
+        }
+    }
+
+    public class CatResponse
+    {
+        public string file { get; set; }
+    }
+}