docs: fix Hiera nav label and stale deprecation content

- nav: rename the duplicate "Hiera" item to "About Hiera"
- hiera_config_yaml_3/4: replace the stale "remove support in Puppet 6"
  notices with accurate text (deprecated, still supported in 8.x for
  backward compatibility, use v5)
- hiera_migrate: add a note that Hiera 5 is the default since Puppet 5
  and most 8.x users do not need the migration guide

Signed-off-by: Michael Harp <mike@mikeharp.com>
Assisted-by: Claude Opus 4.8
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: miharp

_data/nav/openvox_8x.yml

@@ -255,7 +255,7 @@
     link: "designing_convenient_roles.html"
 - text: Hiera
   items:
-  - text: Hiera
+  - text: About Hiera
     link: "hiera_intro.html"
   - text: Interactive Hiera Demo
     link: "hiera_demo.html"

docs/_openvox_8x/hiera_config_yaml_3.md

@@ -29,7 +29,7 @@ This version of Puppet supports three formats for hiera.yaml --- you can use any
 
 ## Important: version 3 is deprecated
 
-Version 3 of hiera.yaml is deprecated, and we plan to remove support for it in Puppet 6.
+Version 3 of hiera.yaml is deprecated and not recommended. OpenVox 8.x still supports it for backward compatibility, but you should use [version 5][v5] instead.
 
 More importantly, it has some major problems:
 

docs/_openvox_8x/hiera_config_yaml_4.md

@@ -22,7 +22,7 @@ v4     | Environment and module layers | Deprecated. A transitional format, used
 
 ## Important: version 4 is deprecated.
 
-Version 4 of hiera.yaml is deprecated, and we plan to remove support for it in Puppet 6.
+Version 4 of hiera.yaml is deprecated and not recommended. OpenVox 8.x still supports it for backward compatibility, but you should use [version 5][v5] instead.
 
 More importantly, version 4 can't use some of Hiera 5's best new features, like custom backends.
 

docs/_openvox_8x/hiera_migrate.md

@@ -21,6 +21,8 @@ title: "Upgrading to Hiera 5"
 [custom_backend_system]: ./hiera_custom_backends.html
 [functions_puppet]: ./lang_write_functions_in_puppet.html
 
+> **Note:** Hiera 5 has been the default since Puppet 5 (2017), so most OpenVox 8.x users already use it and do not need this guide. It remains here for the rare case of migrating very old Hiera 3 data.
+
 Upgrading to Hiera 5 offers some major advantages. A real environment data layer means changes to your hierarchy are now routine and testable,
 using multiple backends in your hierarchy is easier and you can make a custom backend.