- Adds a label with the entry key for autocompletion
- either in the glossary (if it is visible and there is a corresponding entry)
- or invisible during init-glossary
- Use a single label for all usages of the entry in the text. This simplifies the back-referencing logic significantly and also avoids cluttering the auto-complete list
closes https://github.com/swaits/typst-collection/issues/3