Update sidebar external link to open in new tab (TanStack#569)

* Update external link to open in new tab

Add target and rel attributes to external links for security.

* ci: apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: muhammad-paksi

src/components/DocsLayout.tsx

@@ -219,7 +219,12 @@ export function DocsLayout({
             return (
               <li key={i}>
                 {child.to.startsWith('http') ? (
-                  <a href={child.to} className={linkClasses}>
+                  <a
+                    href={child.to}
+                    className={linkClasses}
+                    target="_blank"
+                    rel="noopener noreferrer"
+                  >
                     {child.label}
                   </a>
                 ) : (