feat: add request logging

[ascorbic]

Summary

Adds request logging to both function handlers, as well as an update to the readme explaining what's up.

Test plan

1. Visit the Deploy Preview
2. Load a page
3. View the function logs

Relevant links (GitHub issues, Notion docs, etc.) or a picture of cute animal

Closes #1116

Standard checks:

• Check the Deploy Preview's Demo site for your PR's functionality
• Add docs when necessary

---

🧪 Once merged, make sure to update the version if needed and that it was published correctly.

[netlify]

✔️ Deploy Preview for netlify-plugin-nextjs-demo ready!

🔨 Explore the source changes: 1abba42

🔍 Inspect the deploy log: https://app.netlify.com/sites/netlify-plugin-nextjs-demo/deploys/61e5499c7300ab0007842e9b

😎 Browse the preview: https://deploy-preview-1127--netlify-plugin-nextjs-demo.netlify.app

[netlify]

✔️ Deploy Preview for netlify-plugin-nextjs-static-root-demo ready!

🔨 Explore the source changes: 1abba42

🔍 Inspect the deploy log: https://app.netlify.com/sites/netlify-plugin-nextjs-static-root-demo/deploys/61e5499c9d5b860007b244ac

😎 Browse the preview: https://deploy-preview-1127--netlify-plugin-nextjs-static-root-demo.netlify.app

[netlify]

✔️ Deploy Preview for netlify-plugin-nextjs-nx-monorepo-demo ready!

🔨 Explore the source changes: 1abba42

🔍 Inspect the deploy log: https://app.netlify.com/sites/netlify-plugin-nextjs-nx-monorepo-demo/deploys/61e5499c44c5c40007dcf53a

😎 Browse the preview: https://deploy-preview-1127--netlify-plugin-nextjs-nx-monorepo-demo.netlify.app

[netlify]

✔️ Deploy Preview for netlify-plugin-nextjs-export-demo ready!

🔨 Explore the source changes: 1abba42

🔍 Inspect the deploy log: https://app.netlify.com/sites/netlify-plugin-nextjs-export-demo/deploys/61e5499ce650020007167854

😎 Browse the preview: https://deploy-preview-1127--netlify-plugin-nextjs-export-demo.netlify.app