title: Sonarqube css: How to disable "Unexpected unknown type" rule for selectors with prefix "pr-"
body: <p>I am running sonarqube's CSS analyzer over my Angular 7 project and it is marking all references to material2 elements in my scss as critical bugs.</p>
  
  <p>For example: </p>
  
  <blockquote>
    <p>Unexpected unknown type selector "mat-form-field"</p>
  </blockquote>
  
  <p>How do I add exceptions for selectors with the "mat-" prefix using the sonar-project.properties file?</p>
  
  <p>I've tried a number of different variations on what I've found <a href="https://stylelint.io/user-guide/rules/selector-type-no-unknown/#ignoretypes-regex-regex-string" rel="noreferrer">here</a>  but I've been unable to find an example of this done in a properties file.</p>
  
  <p>I'm looking for something like this:</p>
  
  <p><code>sonar.css.selector-type-no-unknown.ignoreTypes=["/^mat-/"]</code></p>