[7/N][Attention][Docs] Add documentation for attention backends (#32477)

Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>

.pre-commit-config.yaml

@@ -154,6 +154,10 @@ repos:
     files: ^docker/(Dockerfile|versions\.json)$
     pass_filenames: false
     additional_dependencies: [dockerfile-parse]
+  - id: attention-backend-docs
+    name: Check attention backend documentation is up to date
+    entry: python tools/pre_commit/generate_attention_backend_docs.py --check
+    language: python
   # Keep `suggestion` last
   - id: suggestion
     name: Suggestion