Internationalisation Support

Vitepress supports really nice internationalisation (i18n) as can be seen on Vitepress's [homepage](https://vitepress.dev/). There's a guide here https://vitepress.dev/guide/i18n

We use https://github.com/jooy2/vitepress-sidebar to automatically generate our sidebar. To make this work with i18n see this issue https://github.com/jooy2/vitepress-sidebar/issues/106 and a working implementation at https://github.com/dragomano/Light-Portal/tree/master/docs/.vitepress/locales

On the PDF side, if we follow the Vite process of having a language specific folder for each product it should be fairly easy to build individual language PDF's. We'll need to create language specific strings for PDF elements as well.

What are specific languages we should be targeting?

For Get Box:
- [X] English
- Most widely spoken refugee/immigrant languages in the UK
- [ ] Afghanistan (Pashto)
- [ ] Iran (Farsi)
- [ ] Albania (Albanian)
- [ ] Indian (Hindi, Bengali, Punjabi)
- [ ] Iraq (Arabic)
- Potential locations for new Get Box deployments
- [ ] Spanish
- [ ] French
- [ ] German

For Big Box:
- [X] English
- Most commonly spoken languages in the Global South
- [ ] Spanish
- [ ] Arabic
- [ ] Bengali
- [ ] Portuguese
- [ ] French
- [ ] Swahili
- [ ] Urdu
- [ ] Indonesian

Start with the VitePress i18n guide, the vitepress-sidebar issue #106, and the working implementation in Light-Portal's docs/.vitepress/locales. Determine the target languages, then map the required documentation folders, sidebar configuration, and PDF strings; done means language-specific documentation and PDFs can be built for the agreed languages.

Written by the indexing model from the issue text.