Edit README.md
Update README.md
Only add indexed modules to a file document.

In the case of Package::Stash 0.36 the first-in logic was preferring
t/lib/Package/Stash.pm over lib/Package/Stash.pm

Fixes #331.
Merge pull request #329 from CPAN-API/talina/documentation

Talina/documentation
Update README.md

Updates README to use Carton where appropriate.