Hi, maybe it would be nice to provide more documentation examples and information about default values.
For example I created this config:

---
version: "2"
plugins:
  duplication:
    enabled: true
    config:
      languages:
        - javascript
      checks:
        mass_threshold: 50
        similar-code:
          config:
            threshold: 60
        identical-code:
          config:
            threshold: 40

And its raise some questions:

• is it correct?
• why we can't set identical-code: 60 without config: and threshold:?
• can I set mass_threshold: under checks:?
• is my config only allow javascript language?

Also maybe it would be really cool to have a way to visually see the threshold level impact with a code example. Something like code block (default, but with a way to paste your own), a couple of sliders and a result. What do you think, can it be useful?

Regards. Anton.