Enforce use of <>/</> shorthand instead of <React.Fragment>/</React.Fragment>

[wincent]

We can get this via the "jsx-fragments" rule. See: https://github.com/yannickcr/eslint-plugin-react/blob/master/docs/rules/jsx-fragments.md

We can apply this now to the liferay-portal master branch, because that is jsdoc 3.6.3 (older versions would choke on the shorthand).

On liferay-portal-ee master-private, we are still on the older jsdoc; will need to make sure that we update that there before applying this change (we have some React in there, and precisely 5 fragments at the time of writing).