package.json now exports all variations of Ink's stylesheets, both

with and without lib/ prefixes. This allows module-based lookup of

stylesheets to work alongside path-based lookup, which satisfies the two

ways that code may be written, depending on the build system.

Built the package and installed it in Review Board and Djblets. Verified

that this satisfied the Storybook stylesheet loaders, fixing Review Board's

Storybook.