Don't include source maps in packaged component source

[epiccoleman]

Right now, the tsconfig is set up to generate source map files for the compiled code. These are useful for development of the component, but since Typescript source files aren't included in the published package, they're of no use to package users.

As a matter of fact, since I use parcel to run the demo application, I may not even need to generate them with tsc at all... parcel might be doing this for me already.

Either way, they aren't needed in the packaged component.