- upgrade d3 to version 4
- use external d3-textwrap library
    - Problem is it's for d3 v4 only
- node console output colors like Chrome console
- default theme doesn't work for class diagram
- compile less to css
- don't version control generated content, move them to outside project
    - editor
    - dist
    - docs
- what's the correct way to change logLevel as an end user?