Revert rspec-puppet URL — puppetlabs.github.io/rspec-puppet/ is current

rspec-puppet.com is the old site; the canonical docs are at the
GitHub Pages URL per reviewer feedback.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Michael Harp <mike@mikeharp.com>

Author: miharp

docs/_openvox_8x/bgtm.md

@@ -261,7 +261,7 @@ RSpec lets you provide facts, like `os['family']`, in order to test the module i
 
 A typical use of RSpec is to iterate over a list of operating systems, asserting that the package and service should exist in the catalog for every operating system your module supports.
 
-To learn more, see the [rspec-puppet documentation](https://rspec-puppet.com/).
+To learn more, see the [rspec-puppet documentation](https://puppetlabs.github.io/rspec-puppet/).
 
 ### puppetlabs-spec-helper