At the moment, the main and sidebar navigation are all hardwired to the templates. So if a translation team decides to have a different structure or to leave out pages (e.g. the blog section), there will be broken links.
We need to create a Handlebars helper to build (partial) navigation based on the page structure in site.json instead. This way templating would be easier to handle, e.g.
{{navigation}} – renders the main navigation
{{navigation 'about'}} – renders the sub navigation matching the given key