Document the Nginx plugin release (#3588)
Document the Nginx plugin release (#3588)

* Document the Nginx plugin release

* Tweak

* Remove mrueg nginx instructions for now?

* Shipped -> included

* keep order of plugin descriptions consistent with the table

bsmr-misc-forks/letsencrypt,jsha/letsencrypt,stweil/letsencrypt,letsencrypt/letsencrypt,lmcro/letsencrypt,stweil/letsencrypt,letsencrypt/letsencrypt,jsha/letsencrypt,bsmr-misc-forks/letsencrypt,lmcro/letsencrypt