Add github actions Linux build

.github/workflows/cmake-linux.yml

@@ -0,0 +1,34 @@
+name: CMake Windows Build
+
+on: [push, pull_request, workflow_dispatch]
+
+env:
+  BUILD_TYPE: Release
+
+jobs:
+  windows-build:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - uses: actions/checkout@v2
+        with:
+            submodules: 'true'
+
+      - name: Create Build Environment
+        run: cmake -E make_directory ${{github.workspace}}/build-linux
+
+      - name: Configure CMake
+        shell: bash
+        working-directory: ${{github.workspace}}/build-linux
+        run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE
+
+      - name: Build
+        working-directory: ${{github.workspace}}/build-linux
+        shell: bash
+        run: cmake --build . --config $BUILD_TYPE
+
+      - name: Archive artifacts
+        uses: actions/upload-artifact@v2
+        with:
+          name: BeamMP-Launcher
+          path: ${{github.workspace}}/build-linux/Release/BeamMP-Launcher