emscripten installation workflow

Author: ashduino101

.github/workflows/main.yml

@@ -15,6 +15,14 @@ jobs:
       # - name: Build main WASM (FUTURE)
       #   run: wasm-pack build
       # TODO: add MojoShader build script when the rewrite is complete
+      # MS deps
+      - name: Install Emscripten for MojoShader
+        run:  |
+          git clone https://github.com/emscripten-core/emsdk.git
+          cd emsdk
+          ./emsdk install latest
+          ./emsdk activate latest
+          source emsdk_env.sh
       - name: Build encoders
         run: cd encoders && wasm-pack build --out-dir ../js/encoders
       - name: Install dependencies