Tidy up footer copy

Author: csswizardry

_includes/footer.html

@@ -17,7 +17,7 @@
                 <p>I am available for hire to consult, advise, and develop with passionate product teams across the globe.</p>
             </div
            ><div class="layout__item  lap-and-up-one-quarter">
-                <p>I specialise in large, product-based projects where performance and CSS scalability and maintainability are paramount.</p>
+                <p>I specialise in large, product-based projects where performance, scalability, and maintainability are paramount.</p>
             </div
            ><div class="layout__item  lap-and-up-one-half">
                <p><a href="/services/" class="btn  btn--secondary  btn--full">I am currently <strong>considering new projects</strong> for Q1–2 2017.</a></p>