docs(get-started): Documents React version support. (#4513)

Author: edonehoo

packages/documentation-site/patternfly-docs/content/get-started/develop.md

@@ -4,6 +4,7 @@ title: Develop with PatternFly
 section: get-started
 ---
 import './get-started.css';
+import {Alert} from '@patternfly/react-core';
 
 ## Getting started 
 
@@ -19,6 +20,10 @@ In order to develop with PatternFly, you will need to:
 
 ## Develop with React
 
+<Alert title="Version support" variant="info" isInline>
+PatternFly supports the 2 most recent versions of React at a time. PatternFly 6 currently supports React 17 and 18, [with support for React 19 coming soon](https://github.com/orgs/patternfly/projects/16/views/23?pane=issue&itemId=83947829&issue=patternfly%7Cpf-roadmap%7C201).
+</Alert>
+
 [PatternFly's React library](https://github.com/patternfly/patternfly-react) contains a collection of components that you can use to build interfaces with consistent markup, styling, and behavior. It is composed of a number of React packages, which are published in the following npm packages:
 
 * [@patternfly/react-core](https://www.npmjs.com/package/@patternfly/react-core): Most React core components.