Multidomain multisite without a domain mapping plugin

@cfx I just use simple subdomains like site.domain.test, site2domain.test, etc. which works fine out of the box. I started running into problems with URLs like .dev, because they are now legit TLDs. Otherwise, my experience for local dev mirrors @darjanpanic. No /etc/host additions and no need to add subsites to wordpress_sites.yml.