fix id and class definition

docs/_includes/backers.md

@@ -3,5 +3,5 @@
 Find Mocha helpful?  Become a [backer](https://opencollective.com/mochajs#support) and support Mocha with a monthly donation.
 
 <!-- markdownlint-disable MD034 -->
-{: id="_backers" class="image-list" }
+{: #_backers .image-list }
 {% for i in (0..29) %}[![](https://opencollective.com/mochajs/backer/{{ i }}/avatar.jpg)](https://opencollective.com/mochajs/backer/{{ i }}/website){: target="_blank" rel="noopener"}{% endfor %}

docs/_includes/sponsors.md

@@ -3,7 +3,7 @@
 Use Mocha at Work?  Ask your manager or marketing team if they'd help [support](https://opencollective.com/mochajs#support) our project.  Your company's logo will also be displayed on [npmjs.com](http://npmjs.com/package/mocha) and our [GitHub repository](https://github.com/mochajs/mocha#sponsors).
 
 <!-- markdownlint-disable MD034 -->
-{: class="image-list faded-images" }
+{: .image-list .faded-images}
 {% for i in (0..15) %}[![](https://opencollective.com/mochajs/sponsor/{{ i }}/avatar.jpg)](https://opencollective.com/mochajs/sponsor/{{ i }}/website){: target="_blank"} {% endfor %}
 
 <script src="js/avatars.js"></script>

package.json

@@ -65,6 +65,7 @@
     "Cory Thomas (https://github.com/dump247)",
     "cybertk (https://github.com/cybertk)",
     "Daniel Ericsson (https://github.com/monowerker)",
+    "Daniel Ruf (https://github.com/danielruf)",
     "Daniel St. Jules <[email protected]> (https://github.com/danielstjules)",
     "Daniel Stockman <[email protected]> (https://github.com/evocateur)",
     "Dave McKenna <[email protected]> (https://github.com/davemckenna01)",