Update cmake-multi-platform.yml

.github/workflows/cmake-multi-platform.yml

@@ -199,3 +199,14 @@ jobs:
       # Execute tests defined by the CMake configuration. Note that --build-config is needed because the default Windows generator is a multi-config generator (Visual Studio generator).
       # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
       run: ctest --build-config ${{ matrix.build_type }}
+
+    - name: Generate documentation
+      shell: cmake -P {0}
+      run: |
+        execute_process(
+          COMMAND cmake --build build --target docs
+          RESULT_VARIABLE result
+        )
+        if (NOT result EQUAL 0)
+          message(FATAL_ERROR "Building documentation failed")
+        endif()