Airbnb billionaire co-founder Joe Gebbia is growing his team at the U.S. National Design Studio , the Trump initiative focused on improving the government’s online presence. On Monday, Gebbia announced that American designer Peter Arnell joined the team to become the first U.S. Chief Brand Architect. Gebbia shared the news of Arnell’s hire, during the The Wall Street Journal’s “Future of Everything” conference on Monday. Arnell will be joining a group of people that includes Silicon Valley design and software engineering talent, who are singularly focused on reshaping the usability of the U.S. government’s online platforms. In his four-decade career as a brander and marketer, Arnell has worked with major brands like Donna Karan New York, Samsung, Unilever, Pepsi, Reebok, Chrysler, The Home Depot, and others.…