Add webpack

.gitlab-ci.yml

+image: node
+
+cache:
+  paths:
+    - .yarn
+
+before_script:
+  - yarn config set cache-folder "$HOME/.yarn"
+  - yarn install
+  - export PATH="$HOME/.yarn/bin:$PATH"
+
+pages:
+  stage: deploy
+  only:
+    - master
+  artifacts:
+    paths:
+      - build
+  script:
+    - yarn build

package.json

@@ -10,5 +10,12 @@
   "dependencies": {
     "matrix-widget-api": "^0.1.0-beta.13",
     "phaser": "^3.54.0"
+  },
+  "scripts": {
+    "build": "webpack"
+  },
+  "devDependencies": {
+    "webpack": "^5.35.0",
+    "webpack-cli": "^4.6.0"
   }
 }