Template import functionality

I was thinking of adding some functionality, via a second `bin` script that will allow users to specify a folder on their local environment where multiple template folders will exist. Then, `create-js-project`, will load those templates on runtime and provide the templates as options.

This will make the tool infinitely customizable and allow developers to test their templates before submitting them to the project, if they want to do so.

The main points of interest I can think of are:
- How will the path to that folder be stored? Maybe an environment variable?
- What happens if a template folder is not properly structured? It's kind of important to have error handling probably.
- Naming conflicts can cause issues, if the same template name exists in the tool's defaults and imports, which one is prioritized?
- Would it be possible to import templates from multiple locations? Maybe even git repositories?