Promote integration libraries and wrappers

[Krinkle]

We have a plugins page now (https://qunitjs.com/plugins/) but integration libraries such as for ESLint, Sublime, Atom Editor, Ember, Puppeteer etc are not plugins for the QUnit runtime. These are higher level integrations and/or plugins for another thing rather than a plugin for QUnit itself.

It'd be great to list those as well. It could be hand curated initially, or we could adopt a keyword like qunit-integration.\

Ref #42.

[Krinkle]

For Ember, the following article series might a useful reference link:

• https://dev.to/ijlee2/write-tests-like-a-mathematician-part-1-29e9

[Krinkle]

Another one that's more actively maintained:
https://github.com/mmanela/chutzpah