Add product-specific NIST 800-53 control files

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ggbecker

products/rhel10/controls/nist_800_53.yml

@@ -0,0 +1,11 @@
+policy: NIST 800-53 Revision 5 (RHEL10)
+title: NIST Special Publication 800-53 Revision 5 for RHEL10
+id: nist_800_53
+version: Revision 5
+source: https://csrc.nist.gov/publications/detail/sp/800-53/rev-5/final
+product: rhel10
+controls_dir: nist_800_53
+levels:
+  - id: low
+  - id: moderate
+  - id: high