docs for upgrading [CI SKIP]
docs for upgrading [CI SKIP]

thredded/thredded,jayroh/thredded,jayroh/thredded,thredded/thredded,thredded/thredded,jvoss/thredded,jvoss/thredded,thredded/thredded,jayroh/thredded,jvoss/thredded,jayroh/thredded,jvoss/thredded