Add github actions build

Currently this is enabled only for clang/clang++ examples

.github/workflows/cmake.yml

@@ -0,0 +1,47 @@
+name: CMake
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
+  BUILD_TYPE: Release
+
+jobs:
+  build:
+    # The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
+    # You can convert this to a matrix build if you need cross-platform coverage.
+    # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+
+#   - name: Install cc65
+#     run: |
+#       sudo apt-get update
+#       sudo apt-get install cc65
+
+    - name: Install llvm-mos-sdk
+      working-directory: ${{github.workspace}}
+      run: |
+        wget https://github.com/llvm-mos/llvm-mos-sdk/releases/latest/download/llvm-mos-linux.tar.xz
+        tar xf llvm-mos-linux.tar.xz
+
+    - name: Build c/plasma
+      working-directory: ${{github.workspace}}/c/plasma
+      run: |
+        cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/llvm_mos -B build/ .
+        cd build/
+        make
+
+    - name: Build cpp/plasma
+      working-directory: ${{github.workspace}}/cpp/plasma
+      run: |
+        cmake -DCMAKE_PREFIX_PATH=${{github.workspace}}/llvm_mos -B build/ .
+        cd build/
+        make        
+