index.md references categoryLabel in unknown way.

[srawlins]

index.md contains the following top-level text:

{{#categoriesWithPublicLibraries}}
### Category {{{categoryLabel}}}

{{#publicLibrariesSorted}}
{{>library}}
{{/publicLibrariesSorted}}
{{/categoriesWithPublicLibraries}}

categoriesWithPublicLibraries is a field on Package (and nothing else), returning Iterable<LibraryContainer>. LibraryContainer has no such field, categoryLabel. The only class which has such a field is the Category class, which implements LibraryContainer.