Mention Slack in readme
Mention Slack in readme

thenewguy/wagtail,zerolab/wagtail,FlipperPA/wagtail,wagtail/wagtail,mikedingjan/wagtail,kaedroho/wagtail,rsalmaso/wagtail,gasman/wagtail,mikedingjan/wagtail,rsalmaso/wagtail,thenewguy/wagtail,timorieber/wagtail,thenewguy/wagtail,FlipperPA/wagtail,rsalmaso/wagtail,timorieber/wagtail,nealtodd/wagtail,mixxorz/wagtail,torchbox/wagtail,wagtail/wagtail,wagtail/wagtail,gasman/wagtail,kaedroho/wagtail,mixxorz/wagtail,jnns/wagtail,mikedingjan/wagtail,kaedroho/wagtail,wagtail/wagtail,mikedingjan/wagtail,thenewguy/wagtail,takeflight/wagtail,jnns/wagtail,gasman/wagtail,timorieber/wagtail,takeflight/wagtail,nimasmi/wagtail,thenewguy/wagtail,nimasmi/wagtail,gasman/wagtail,kaedroho/wagtail,nealtodd/wagtail,kaedroho/wagtail,gasman/wagtail,FlipperPA/wagtail,nealtodd/wagtail,mixxorz/wagtail,rsalmaso/wagtail,torchbox/wagtail,nealtodd/wagtail,zerolab/wagtail,zerolab/wagtail,wagtail/wagtail,zerolab/wagtail,FlipperPA/wagtail,takeflight/wagtail,timorieber/wagtail,jnns/wagtail,mixxorz/wagtail,zerolab/wagtail,nimasmi/wagtail,nimasmi/wagtail,torchbox/wagtail,mixxorz/wagtail,takeflight/wagtail,rsalmaso/wagtail,torchbox/wagtail,jnns/wagtail