docs: fix examples

Author: tannerlinsley

docs/src/pages/examples/basic.mdx

@@ -8,7 +8,7 @@ toc: false
 - [View Source](https://github.com/tannerlinsley/react-query/tree/main/examples/basic)
 
 <iframe
-  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/master/examples/basic?autoresize=1&fontsize=14&theme=dark"
+  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/main/examples/basic?autoresize=1&fontsize=14&theme=dark"
   title="tannerlinsley/react-query: basic"
   sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
   style={{

docs/src/pages/examples/custom-hooks.mdx

@@ -8,7 +8,7 @@ toc: false
 - [View Source](https://github.com/tannerlinsley/react-query/tree/main/examples/custom-hooks)
 
 <iframe
-  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/master/examples/custom-hooks?autoresize=1&fontsize=14&theme=dark"
+  src="https://codesandbox.io/embed/github/tannerlinsley/react-query/tree/main/examples/custom-hooks?autoresize=1&fontsize=14&theme=dark"
   title="tannerlinsley/react-query: custom-hooks"
   sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
   style={{