ci: configure hook exclusions and fix README lint (MD040/MD056)

.pre-commit-config.yaml

@@ -1,4 +1,13 @@
 # cSpell:ignore autofix autoupdate
+# Excluded: verbatim GPL license, auxiliary shell scripts with intentional
+# in-string formatting, and the soon-to-be-removed standalone workflow.
+exclude: |
+  (?x)^(
+    LICENSE\.md|
+    benchmark/|
+    docker/reprex/|
+    \.crow/build-r-minor-sensitive-packages\.yaml
+  )
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v6.0.0