Correct internal links for each localisation

Currently, links in pages (_not_ on the sidebar) are hardcoded to paths in the `en` localisation. For example, in the [emoji key page in french](https://allcontributors.org/fr/reference/emoji-key/) the first two links for "Bot" and "CLI" both link to the `/en/` localisation, rather than `/fr/`.

It will be jarring for readers to be moved between languages like this, and it is inconsistent with the behaviour of the sidebar.

Ways we could approach this,

- An Astro component to write/rewrite links based on the selected locale (@trueberryless any ideas or experience here?)
- Explicitly writing the links in each translation