docs: add Sign-up Page link to all-components documentation

Author: yuito-it

docs/data/toolpad/core/all-components/all-components.md

@@ -8,3 +8,4 @@
 - [Dashboard Layout](/toolpad/core/react-dashboard-layout/)
 - [Page Container](/toolpad/core/react-page-container/)
 - [Sign-in Page](/toolpad/core/react-sign-in-page/)
+- [Sign-up Page](/toolpad/core/react-sign-up-page/)