Add code formatting check

.forgejo/workflows/build.yaml

@@ -4,6 +4,19 @@ on: [push]
 name: Build
 
 jobs:
+  format:
+    name: Format
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Check out the code
+        uses: actions/checkout@v4
+      - name: Install clang-format
+        run: |
+          sudo apt-get update
+          sudo apt-get -y install clang-format
+      - name: Check the code's formatting
+        run: "clang-format --dry-run src/*.h src/*.cpp 2>&1 | tee fmt.log; [ ! -s fmt.log ]"
+
   build:
     name: Build
     runs-on: ubuntu-22.04