Updated Termdash API (markdown)

Termdash-API.md

@@ -11,10 +11,30 @@ The [termdash](https://github.com/mum4k/termdash/blob/master/termdash.go) packag
 
 The public API surface of this package consists of the following:
 
-## [Run](https://github.com/mum4k/termdash/blob/c861ecef303ac648f926597f28c9f44994a1ca8b/termdash.go#L91-L103) function:
+## [termdash.Run](https://github.com/mum4k/termdash/blob/c861ecef303ac648f926597f28c9f44994a1ca8b/termdash.go#L91-L103):
 
-The **Run** function provides the simplest way to run a Termdash based application.
+The **Run** function provides the simplest way to run a Termdash based application. Run blocks until the provided context expires, therefore we need a trigger to close the context, e.g. a keyboard shortcut or a timeout. When Termdash is started using this function, the screen is redrawn periodically.
+
+The following code snippet starts Termdash with an empty container and no widgets. Termdash will quit after 5 seconds when the context expires.
 
 ```go
+// Create the terminal.
+t, err := termbox.New()
+if err != nil {
+    fmt.Errorf("termbox.New => %v", err)
+}
+defer t.Close()
 
+// Create the container without widgets.
+c, err := container.New(t)
+if err != nil {
+    fmt.Errorf("termbox.New => %v", err)
+}
+
+// Termdash runs until the context expires.
+ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+defer cancel()
+if err := Run(ctx, t, c); err != nil {
+    panic(err)
+}
 ```