Add webpack demo example

[hofbi]

---

Changes are visible to end-users: yes/no

• Searched for relevant documentation and updated as needed: yes/no
• Breaking change (forces users to change their own code or config): yes/no
• Suggested release notes appear below: yes/no

Test plan

• Covered by existing test cases
• New test cases added
• Manual testing; please provide instructions so we can reproduce:

[aspect-workflows]

Test

⚠️ GitHub Actions build #260 failed.

---

Lint

.

0 issues require fixes
0 issues can be fixed automatically

---

Buildifier      Format      Gazelle

[codecov]

Welcome to Codecov 🎉

Once you merge this PR into your default branch, you're all set! Codecov will compare coverage reports and display results in all future pull requests.

Thanks for integrating Codecov - We've got you covered ☂️