Add isDisabled to EnovyOption

The select component that the app store uses recognizes this and behaves accordingly.

Author: JustWalters

src/internal/EnvoyOption.ts

@@ -1,6 +1,7 @@
 type EnvoyOption = {
   label: string,
   value: string,
+  isDisabled?: boolean,
 };
 
 export default EnvoyOption;