Introduce clang-format (#240)

.github/workflows/format.yml

@@ -0,0 +1,20 @@
+name: Format
+
+on: [push, pull_request]
+
+jobs:
+  clang-format:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Run clang-format
+      run: |
+        pipx run "clang-format>=17,<18" \
+          --Werror \
+          --dry-run \
+          --style=file \
+          ISLE/*.cpp ISLE/*.h \
+          LEGO1/*.cpp LEGO1/*.h \
+          LEGO1/realtime/*.cpp LEGO1/realtime/*.h