fix: MenuItems can accept String value now

Overview This PR is for this issue #1390. The MenuItem component does not accept String type values, while all the examples in the docs say that it does! Made a change to its prop types that should solve this issue.

Issue:

This demonstrates the issue. It throws an error if 'String' value is passed as 'secondaryText' to 'ModalItem'. Note: This example is importing and using evergreen component.

Solution:

Open this sandbox

Step1:

Open the App.tsx file and see passing string value to 'secondaryText' throws an error.

Step2:

Now go to MenuItem.tsx. The custom component is defined here. I tried to reproduce the actual component but at a very basic level. But, the role of types can be understood.

Step3:

Comment lIne 4 and un-comment Line 5.

The error is gone! Because the type String is added to the type declaration for secondaryText.

This is what my PR solves.

Documentation

[ ] Updated Typescript types and/or component PropTypes
[ ] Added / modified component docs
[ ] Added / modified Storybook stories

segmentio / evergreen