Added separate web build workflow.

Eventually this should update the samples on the website.

.github/workflows/web.yml

@@ -0,0 +1,47 @@
+name: 🌎 Web
+on: [push, pull_request]
+
+concurrency:
+  group: ci-${{github.actor}}-${{github.head_ref || github.run_number}}-${{github.ref}}-web
+  cancel-in-progress: true
+
+jobs:
+  web:
+    name: Web
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        build-type:
+          - Release
+          #- Debug
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      # - name: Cache
+      #   id: cache-system-libraries
+      #   uses: actions/cache@v2
+      #   with:
+      #     path: emsdk-cache
+      #     key: emsdk-${{ runner.os }}
+
+      - name: Emscripten
+        uses: mymindstorm/setup-emsdk@v11
+        with:
+          #actions-cache-folder: 'emsdk-cache'
+          no-cache: true
+          version: 3.1.17
+
+      - name: Verify Emscripten
+        run: emcc -v
+
+      - name: CMake
+        run: emcmake script/cmake_emscripten.sh build -DCMAKE_BUILD_TYPE=${{ matrix.build-type }} -DURHO3D_LIB_TYPE=static -DURHO3D_PROFILING=0
+
+      - name: Build
+        run: cmake --build build --parallel 2 --config ${{ matrix.build-type }}
+
+      - name: Publish
+        if: 0
+        # TODO: port the ci_publish_web: task from the rakefile