Document some known third-party plugins
Document some known third-party plugins

dietsche/letsencrypt,stweil/letsencrypt,brentdax/letsencrypt,wteiken/letsencrypt,dietsche/letsencrypt,mitnk/letsencrypt,bsmr-misc-forks/letsencrypt,letsencrypt/letsencrypt,stweil/letsencrypt,jtl999/certbot,lmcro/letsencrypt,DavidGarciaCat/letsencrypt,brentdax/letsencrypt,letsencrypt/letsencrypt,mitnk/letsencrypt,jsha/letsencrypt,wteiken/letsencrypt,jsha/letsencrypt,DavidGarciaCat/letsencrypt,lmcro/letsencrypt,jtl999/certbot,bsmr-misc-forks/letsencrypt