feat(package): package source files for debugging

Package source files, next to the normal JS files and map files for debugging purposes.

BREAKING CHANGE: Files are now published under `dist` directory. Deep imports (which is a bad practice at best) should be updated accordingly.

.npmignore

@@ -1,8 +1,7 @@
 **/*
 !bin/**
 !src/**
-src/**/*.map
-src/**/*.ts
+!dist/src/**
 !src/**/*.d.ts
 !readme.md
 !CHANGELOG.md