added link to qunit-inject dependency injection plugin

Added link to [qunit-inject](https://github.com/bahmutov/qunit-inject), which allows things like

```js
QUnit.module('QUnit.assert tests WITH injection', {
  a: 42,
  b: 1
});
QUnit.test('injection sandwich', function (b, assert, a) {
  assert.equal(a, 42, 'assert works');
  assert.equal(b, 1, 'b value');
});
```