[api-documenter] namespace and interface with same name documents only the namespace

[singpolyma]

Summary

I have an interface named mynamespace.Persistence and also a namespace with more classes mynamespace.persistence.Stuff the markdown files written in markdown mode all have lowercase names so these end up with the same name and I only end up with a file documenting the namespace not the interface. I get a link to what should be the interface documentation, but it's the same page as the namespace, having been (it seems) overwritten.

Repro steps

Have a namespace and interface with same names (different case).

npx @microsoft/api-extractor run -c npm/api-extractor.json
npx @microsoft/api-documenter markdown -i tmp -o docs/js/

Standard questions

Please answer these questions to help us investigate your issue more quickly:

Question	Answer
Operating system?	Linux
Documentation target?	Markdown
Would you consider contributing a PR?	Yes