docs(option/orElse): add deprecation message

Co-authored-by: Pedro Castro <[email protected]>

Author: glennsl

src/Core__Option.resi

@@ -214,7 +214,7 @@ Option.orElse(None, Some(1066) == Some(1066)
 Option.orElse(None, None) == None
 ```
 */
-@deprecated
+@deprecated("Use `or` instead")
 let orElse: (option<'a>, option<'a>) => option<'a>
 
 /**