Normalize Turtle with pre-commit hook

No effects were observed on Make-managed files.

Disclaimer:
Participation by NIST in the creation of the documentation of mentioned
software is not intended to imply a recommendation or endorsement by the
National Institute of Standards and Technology, nor is it intended to
imply that any specific software is necessarily the best available for
the purpose.

Signed-off-by: Alex Nelson <alexander.nelson@nist.gov>

.pre-commit-config.yaml

@@ -12,3 +12,9 @@ repos:
     hooks:
       - id: isort
         name: isort (python)
+  - repo: https://github.com/casework/rdf-toolkit-action
+    rev: 2.0.3
+    hooks:
+      - id: rdf-toolkit-normalizer
+        args:
+          - --autofix