Update readme to fix typo and add roadmap

Author: erodewald

README.md

@@ -37,11 +37,15 @@ import smartapp from '@smartthings/smartapp'
 ## Highlights
 
 - [x] Javascript API hides details of REST calls and authentication.
-- [x] Event handler framework dispatches lifecycle evebnts to named event handlers.
+- [x] Event handler framework dispatches lifecycle events to named event handlers.
 - [x] Configuration page API simplifies page definition.
 - [x] Integrated [i18n](https://www.npmjs.com/package/i18n) framework provides configuration page localization.
 - [x] [Winston](https://www.npmjs.com/package/winston) framework manges log messages.
 
+## Roadmap
+
+![Roadmap](doc/roadmap-2019.png)
+
 ## Example
 
 The following example is the equivalent of the original SmartThings Groovy _Let There Be Light_ app that turns on and off a light when a door opens and closes.