Add a blog article about Zuul's 10th Anniversary.
Also clean up some stray trailing whitespace and extended UTF-8
characters which crept in during a previous addition.
Change-Id: I47d89b6ed14c155368315f66087f7ce466e3caf0
Co-Authored-By: Sunny Cai <sunny@openinfra.dev>
Co-Authored-By: Clark Boylan <clark.boylan@gmail.com>