NPM package `main` (entry) doesn't exist

[turboMaCk]

Related to my comment in #58 (comment)

Current NPM package is broken. It declares main to be lib/index.js but it does neither include nor produce this file.

Furthermore tsconfig.json is also not included in the package due to it not being included in files so option of using tsc to compile the lib would also require change there.

To fix this:

• Either npm package should contain already compile lib directory prepare
• Or package should both include tsconfig and necessary dependencies and build this dir in post-install.

ping @dhkatz