[DiapDealer]

That's not feasible. Our "Site" is auto generated by a GitHub repository. It is automatically updated by our GitHub release process to point to a specifically named artifact attached to the latest release of the Sigil User Guide GitHub repository. So it's not nearly as simple as "add an interface element." Not to mention that even if we could get it to just magically work, we'd still need to rely upon links to external sites that we have no control over. We would have to rely on others to help us fix the myriad of things that could break under such conditions.

I'd be happy to add links to third-party translations of our user guide in a subsection of our sigil-ebook.com documentation page. But it's not going to be a choose-your-language kind of option. They would also have to be links that are going to be permanently available.