Fix guide links in README (#3117)

Author: ChristopherFry

site/guides/README.md

@@ -1,8 +1,7 @@
 # Reference
 
-- [The Rationale behind kpt](guides/rationale.md)
-- [The Rationale behind kpt](guides/rationale.md)
-- [Namespace provisioning CLI](guides/namespace-provisioning-cli.md)
-- [Namespace provisioning UI](guides/namespace-provisioning-ui.md)
-- [Porch Installation Guide](guides/porch-installation.md)
-- [Porch User Guide](guides/porch-user-guide.md)
+- [The Rationale behind kpt](rationale.md)
+- [Namespace provisioning CLI](namespace-provisioning-cli.md)
+- [Namespace provisioning UI](namespace-provisioning-ui.md)
+- [Porch Installation Guide](porch-installation.md)
+- [Porch User Guide](porch-user-guide.md)