Merge pull request #601 from Code-ScottLe/dev

Add back in documentation for background task helper

Author: deltakosh

docs/helpers/BackgroundTaskHelper.md

@@ -0,0 +1,50 @@
+# Background Task Helper
+
+The **Background Task Helper** helps users interacting with background tasks in an easier manner. 
+
+## Example
+
+```csharp
+	
+    // Be sure to include the using at the top of the file:
+    //using Microsoft.Toolkit.Uwp;
+    //using Windows.ApplicationModel.Background;
+
+    // Register a normal, seperate process, background task
+    BackgroundTaskRegistration registered = BackgroundTaskHelper.Register("TaskName","TaskEntryPoint", new TimeTrigger(15, true));
+
+    // This can also be written using the overload of Register with Type parameter.
+    BackgroundTaskRegistration registered = BackgroundTaskHelper.Register(typeof(BackgroundTaskClass), new TimeTrigger(15, true));
+
+    // With condition
+    BackgroundTaskRegistration registered = 
+        BackgroundTaskHelper.Register(typeof(BackgroundTaskClass), 
+                                      new TimeTrigger(15, true), 
+                                      false, true, 
+                                      new SystemCondition(SystemConditionType.InternetAvailable));
+
+    // 2 or more conditions
+    BackgroundTaskRegistration registered = 
+        BackgroundTaskHelper.Register(typeof(BackgroundTaskClass), 
+                                      new TimeTrigger(15, true), 
+                                      false, true, 
+                                      new SystemCondition(SystemConditionType.InternetAvailable), 
+                                      new SystemCondition(SystemConditionType.UserPresent));
+
+    // Register a single process background task (Anniversary Update and later ONLY)
+    BackgroundTaskRegistration registered = BackgroundTaskHelper.Register("TaskName", new TimeTrigger(15, true))
+
+```
+
+You can find more examples in our [unit tests](https://github.com/Microsoft/UWPCommunityToolkit/blob/master/UnitTests/Helpers/Test_BackgroundTaskHelper.cs)
+
+## Requirements (Windows 10 Device Family)
+
+| [Device family](http://go.microsoft.com/fwlink/p/?LinkID=526370) | Universal, 10.0.10586.0 or higher |
+| --- | --- |
+| Namespace | Microsoft.Toolkit.Uwp |
+
+## API
+
+* [Background Task source code](https://github.com/Microsoft/UWPCommunityToolkit/blob/master/Microsoft.Toolkit.Uwp/Helpers/BackgroundTaskHelper.cs)
+