New configuration package for TypeDoc documentation

[holgerd77]

Since auto-generated documentation is applied on most of the libraries (and probably should be extended to all), we should also add a config package for documentation here.

The util package TypeScript PR ethereumjs/ethereumjs-util#170 already gives some boilerplate/template for TypeDoc usage, there should also be some common npm script, see #10.

Note: Configuration file docs for TypeDoc is a bit hard to find, here is some entry point.

[holgerd77]

Note:
Package name should be tool agnostic, so ethereumjs-config-docs.