docs: point offline example to /beta

Author: TkDodo

docs/src/pages/examples/offline.mdx

@@ -4,11 +4,11 @@ title: Offline Queries and Mutations
 toc: false
 ---
 
-- [Open in CodeSandbox](https://codesandbox.io/s/github/tannerlinsley/react-query/tree/alpha/examples/offline)
-- [View Source](https://github.com/tannerlinsley/react-query/tree/alpha/examples/offline)
+- [Open in CodeSandbox](https://codesandbox.io/s/github/tannerlinsley/react-query/tree/beta/examples/offline)
+- [View Source](https://github.com/tannerlinsley/react-query/tree/beta/examples/offline)
 
 <iframe
-  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/alpha/examples/offline?autoresize=1&fontsize=14&theme=dark"
+  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/beta/examples/offline?autoresize=1&fontsize=14&theme=dark"
   title="tannerlinsley/react-query: offline"
   sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
   style={{