docs: Add Webhook example. (#1241)

* Add Webhook example.

* Fix spacing.

* Update to use webhook URL ctor.

Discord.Net.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
+# Visual Studio Version 16
-VisualStudioVersion = 15.0.27004.2009
+VisualStudioVersion = 16.0.28407.52
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Discord.Net.Core", "src\Discord.Net.Core\Discord.Net.Core.csproj", "{91E9E7BD-75C9-4E98-84AA-2C271922E5C2}"
 EndProject
@@ -32,6 +32,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "02_commands_framework", "sa
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "03_sharded_client", "samples\03_sharded_client\03_sharded_client.csproj", "{9B4C4AFB-3D15-44C6-9E36-12ED625AAA26}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "04_webhook_client", "samples\04_webhook_client\04_webhook_client.csproj", "{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}"
+EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Examples", "Examples", "{D1F0271E-0EE2-4B66-AC3D-9871B7E1C4CF}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Discord.Net.Examples", "src\Discord.Net.Examples\Discord.Net.Examples.csproj", "{7EA96B2B-4D71-458D-9423-839362DC38BE}"
@@ -178,6 +180,18 @@ Global
 		{9B4C4AFB-3D15-44C6-9E36-12ED625AAA26}.Release|x64.Build.0 = Release|Any CPU
 		{9B4C4AFB-3D15-44C6-9E36-12ED625AAA26}.Release|x86.ActiveCfg = Release|Any CPU
 		{9B4C4AFB-3D15-44C6-9E36-12ED625AAA26}.Release|x86.Build.0 = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|x64.Build.0 = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Debug|x86.Build.0 = Debug|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|Any CPU.Build.0 = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|x64.ActiveCfg = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|x64.Build.0 = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|x86.ActiveCfg = Release|Any CPU
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562}.Release|x86.Build.0 = Release|Any CPU
 		{7EA96B2B-4D71-458D-9423-839362DC38BE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{7EA96B2B-4D71-458D-9423-839362DC38BE}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7EA96B2B-4D71-458D-9423-839362DC38BE}.Debug|x64.ActiveCfg = Debug|Any CPU
@@ -204,6 +218,7 @@ Global
 		{F2FF84FB-F6AD-47E5-9EE5-18206CAE136E} = {BB59D5B5-E7B0-4BF4-8F82-D14431B2799B}
 		{4E1F1F40-B1DD-40C9-A4B1-A2046A4C9C76} = {BB59D5B5-E7B0-4BF4-8F82-D14431B2799B}
 		{9B4C4AFB-3D15-44C6-9E36-12ED625AAA26} = {BB59D5B5-E7B0-4BF4-8F82-D14431B2799B}
+		{88B77A5B-0BC0-4E99-8FD9-D83F6999F562} = {BB59D5B5-E7B0-4BF4-8F82-D14431B2799B}
 		{7EA96B2B-4D71-458D-9423-839362DC38BE} = {D1F0271E-0EE2-4B66-AC3D-9871B7E1C4CF}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution

samples/04_webhook_client/04_webhook_client.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <RootNamespace>_04_webhook_client</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Discord.Net.Webhook\Discord.Net.Webhook.csproj" />
+  </ItemGroup>
+
+</Project>

samples/04_webhook_client/Program.cs

@@ -0,0 +1,34 @@
+using Discord;
+using Discord.Webhook;
+using System.Threading.Tasks;
+
+namespace _04_webhook_client
+{
+    // This is a minimal example of using Discord.Net's Webhook Client
+    // Webhooks are send-only components of Discord that allow you to make a POST request
+    // To a channel specific URL to send a message to that channel.
+    class Program
+    {
+        static void Main(string[] args)
+            => new Program().MainAsync().GetAwaiter().GetResult();
+
+        public async Task MainAsync()
+        {
+            // The webhook url follows the format https://discordapp.com/api/webhooks/{id}/{token}
+            // Because anyone with the webhook URL can use your webhook
+            // you should NOT hard code the URL or ID + token into your application. 
+            using (var client = new DiscordWebhookClient("https://discordapp.com/api/webhooks/123/abc123"))
+            {
+                var embed = new EmbedBuilder
+                {
+                    Title = "Test Embed",
+                    Description = "Test Description"
+                };
+
+                // Webhooks are able to send multiple embeds per message
+                // As such, your embeds must be passed as a collection. 
+                await client.SendMessageAsync(text: "Send a message to this webhook!", embeds: new[] { embed.Build() });
+            }
+        }
+    }
+}