Updated Termdash API (markdown)

Termdash-API.md

@@ -111,7 +111,7 @@ if err := ctrl.Redraw(); err != nil {
 
 ## [termdash.ErrorHandler](https://github.com/mum4k/termdash/blob/1c6947618b08ae236959763efd07278be5f03211/termdash.go#L64-L71):
 
-The **termdash.ErrorHandler** function is used to provide a custom error handler. If not provided, the application will panic on all runtime errors. An error handler is a function that receives the error and decides what to do. This function must be thread-safe, since Termdash delivers events concurrently.
+The **termdash.ErrorHandler** function is used to provide a custom error handler. If not provided, the application will panic on all runtime errors. An error handler is a function (a callback) that receives the error and decides what to do. This function must be thread-safe, since Termdash delivers events concurrently.
 
 The following example shows initialisation of Termdash with an error handler that just logs the error message:
 
@@ -135,4 +135,28 @@ if err != nil {
 }
 defer ctrl.Close()
 ```
-## [termdash.ErrorHandler](https://github.com/mum4k/termdash/blob/1c6947618b08ae236959763efd07278be5f03211/termdash.go#L64-L71):
+## [termdash.KeyboardSubscriber](https://github.com/mum4k/termdash/blob/275d95ad418b6ecca8817de4b013b440fc9abbe6/termdash.go#L74-L81):
+
+The **termdash.KeyboardSubscriber** function can be used by the developer to provide an additional subscriber to keyboard events. A keyboard subscriber is a function (a callback) that processes keyboard events. This function must be thread-safe, since Termdash delivers events concurrently. Providing an additional keyboard subscriber is completely optional and doesn't affect any of Termdash functionalities.
+
+The following example shows initialisation of Termdash with a keyboard subscriber that terminates the application when the letter 'q' or 'Q' is pressed on the keyboard.
+
+```go
+// Create terminal t and container c as in the examples above.
+
+// Context for Termdash, the application quits when this expires.
+// Since the context has no deadline, it will only expire when cancel() is called.
+ctx, cancel := context.WithCancel(context.Background())
+
+// A keyboard subscriber that terminates the application by cancelling the context.
+quitter := func(k *terminalapi.Keyboard) {
+  if k.Key == 'q' || k.Key == 'Q' {
+    cancel()
+  }
+}
+
+// Termdash will run until one of the two letters is pressed.
+if err := termdash.Run(ctx, t, c, termdash.KeyboardSubscriber(quitter)); err != nil {
+    return fmt.Errorf("termdash.Run => %v", err)
+}
+```