Revert "ci: update docs script destination path (#990)" (#1094)

This reverts commit d10ad6d.

The reference.md file was moved back to content/docs/deploy/k8s.

Author: kenjenkins

scripts/open-docs-pull-request.sh

@@ -3,7 +3,7 @@ set -euo pipefail
 
 source_path="reference.md"
 destination_repo="pomerium/documentation"
-destination_path="content/docs/k8s"
+destination_path="content/docs/deploy/k8s"
 destination_base_branch="main"
 destination_head_branch="update-k8s-reference-$GITHUB_SHA"