👷 Adds action to get the compressed size of a PR

.github/workflows/get-size.yml

@@ -0,0 +1,9 @@
+# Adds a comment to new PRs, showing the compressed size and size difference of new code
+name: Compressed Size
+on: [pull_request]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: preactjs/compressed-size-action@v2