Automated building and execution

[gladyshcodes]

What

Create a script similar to nodemon that would listen to changes and rebuild the project for us on the fly.

Why

Now, in order to test newly made changes, you will need to build packages/shortest, and then re-run tests. That takes some development time.

[m2rads]

I think this could improve the developer experience. If you end up using a new lib for this, please be sure to add it as devDependency.