CI: Use compressed-size-action to report asset size changes to PRs

Author: Turbo87

.github/workflows/asset-size.yml

@@ -0,0 +1,15 @@
+name: Asset Size
+
+on: [pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: Turbo87/compressed-size-action@crates
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          pattern: "dist/**/*.{js,css}"
+          strip-hash: "-[0-9a-f]{32}"