chore: add CI comment

Author: natemoo-re

.github/workflows/ci.yml

@@ -28,6 +28,8 @@ jobs:
           cache: "pnpm"
       - if: ${{ steps.cache-node.outputs.cache-hit != 'true' }}
         run: pnpm install
+      # TODO: is this manual build step actually needed?
+      # `prepack` hook _should_ run but doesn't seem to.
       - run: pnpm run build
       - uses: changesets/action@v1
         if: ${{ github.event_name != 'pull_request' }}