- introduce new rules for the Category

- the rules can be used to match specified `Properties` with a `RegExp` (uses `test`) - to add them into a category
  - This allows more complex changelogs to be constructed, which for example want all `OPEN` PRs in one category

__tests__/transform.test.ts

@@ -1,7 +1,7 @@
 import {buildChangelog} from '../src/transform'
 import {PullRequestInfo} from '../src/pullRequests'
 import moment from 'moment'
-import {Configuration, DefaultConfiguration} from '../src/configuration'
+import {DefaultConfiguration} from '../src/configuration'
 import {DefaultDiffInfo} from '../src/commits'
 
 jest.setTimeout(180000)