add language picker

[alifeee]

• language picker (for both toki pona speakers and English outsiders)

[ngsilverman]

Here's some relevant documentation about Eleventy internationalization: https://www.11ty.dev/docs/i18n/

[alifeee]

we have several pages. I don't think we need separate versions of any of them

• homepage - https://liputenpo.org/ (no content to translate)
• lipu - https://liputenpo.org/lipu/nanpa-linja/ (already has English translations)
• toki - https://liputenpo.org/toki/nanpa-kalama/kulupu-li-toki-pona-lon-ma-ite/ (cannot translate)
• sona - https://liputenpo.org/sona/ (this is already in English)
• lipu ante - https://liputenpo.org/lipu-ante/ (this has no text)

Perhaps the only thing missing is what someone should click if they end up on the site and do not know toki pona.. how should they know to click sona to get to the FAQ? Maybe a link to sona in the footer?