fix typo

Example/README.md

@@ -2,6 +2,6 @@
 
 This example shows how to use the Terminal.Gui library to create a simple GUI application in C#.
 
-This is the same code found in the Termina.Gui README.md file.
+This is the same code found in the Terminal.Gui README.md file.
 
 See [README.md](https://github.com/gui-cs/Terminal.Gui) for a list of all Terminal.Gui samples.