added minimal USE_SPA=1 doc
added minimal USE_SPA=1 doc

monarch-initiative/monarch-app,kshefchek/monarch-app,kshefchek/monarch-app,kshefchek/monarch-app,kshefchek/monarch-app,monarch-initiative/monarch-app,monarch-initiative/monarch-app,kshefchek/monarch-app,monarch-initiative/monarch-app,monarch-initiative/monarch-app