Dynamic Open Graph Social Images

### Epic

_No response_

### Description

With our imminent switch to Netlify, building our serverless and edge functions has become a possibility. A common usecase for these are dynamic OpenGraph images, which would be very valuable for our **Docs** & **Handbook** links.

This would mean that we could use the title/content of these pages to generate an image when shared on socials, that is unique to each page, e.g.:

- https://twitter.com/jh3yy/status/1629274767260897281
- https://sst.dev/chapters/dynamically-generate-social-share-images-with-serverless.html
- https://posthog.com/blog/dynamic-open-graph-images
- https://github.blog/2021-06-22-framework-building-open-graph-images/

### Acceptance Criteria

- [x] [Design base template for Handbook & Docs tiles](https://github.com/flowforge/website/issues/574)
- [ ] Add a serverless function to automatically populate these templates given the content of a particular page from our handbook & docs.