fix: make preview the main entry point for 1.27.0-rc1 docs

Signed-off-by: Gabriele Bartolini <[email protected]>

Author: gbartolini

content/docs/1.27.md content/docs/preview.mdcontent/docs/1.27.md renamed to content/docs/preview.md

@@ -1,6 +1,6 @@
 ---
 release:  1.27.0-rc1
-location: /documentation/1.27.0-rc1
+location: /documentation/preview
 release_date: 29 Jul 2025
 release_notes: https://github.com/cloudnative-pg/cloudnative-pg/releases/tag/v1.27.0-rc1
 ---