Small Typo Fix (#3653)

"more then one screen" should be "more than one screen"

docs/docs/layout-types.md

 ## stack
 
 Support children layouts of any kind.
-A stack can be initialised with more then one screen, in which case the last screen will be presented at the top of the stack.
+A stack can be initialised with more than one screen, in which case the last screen will be presented at the top of the stack.
 
 ```js
 const stack = {