Update HIP index

Signed-off-by: Marcin Owsiany <[email protected]>

Author: porridge

hips/README.md

@@ -34,4 +34,5 @@ restricted markdown format and can be found in the
 - [hip-0023: Utilize Server Side Apply for installs/upgrades](hip-0023.md)
 - [hip-0024: Improve the Helm Documentation](hip-0024.md)
 - [hip-0025: Better Support for Resource Creation Sequencing](hip-0025.md)
-- [hip:0026: H4HIP: Wasm plugin system](hip-0026.md)
+- [hip-0026: H4HIP: Wasm plugin system](hip-0026.md)
+- [hip-0027: Handling unknown hook-delete-policy values](hip-0027.md)