README: documentation link at the top.
README: documentation link at the top.

Hopefully helps to mitigate problems mentioned in
https://groups.google.com/a/letsencrypt.org/forum/#!topic/client-dev/4xpVpy4EVz0

wteiken/letsencrypt,rlustin/letsencrypt,jtl999/certbot,jsha/letsencrypt,jmhodges/letsencrypt,beermix/letsencrypt,lbeltrame/letsencrypt,Jadaw1n/letsencrypt,Jonadabe/letsencrypt,Hasimir/letsencrypt,riseofthetigers/letsencrypt,tyagi-prashant/letsencrypt,VladimirTyrin/letsencrypt,beermix/letsencrypt,sapics/letsencrypt,dietsche/letsencrypt,armersong/letsencrypt,stweil/letsencrypt,martindale/letsencrypt,stewnorriss/letsencrypt,modulexcite/letsencrypt,twstrike/le_for_patching,piru/letsencrypt,fmarier/letsencrypt,lbeltrame/letsencrypt,Jadaw1n/letsencrypt,thanatos/lets-encrypt-preview,bestwpw/letsencrypt,dietsche/letsencrypt,lmcro/letsencrypt,Sveder/letsencrypt,modulexcite/letsencrypt,jtl999/certbot,letsencrypt/letsencrypt,deserted/letsencrypt,xgin/letsencrypt,wteiken/letsencrypt,PeterMosmans/letsencrypt,Hasimir/letsencrypt,mitnk/letsencrypt,ghyde/letsencrypt,hsduk/lets-encrypt-preview,brentdax/letsencrypt,tyagi-prashant/letsencrypt,goofwear/letsencrypt,xgin/letsencrypt,Bachmann1234/letsencrypt,jmaurice/letsencrypt,kuba/letsencrypt,Sveder/letsencrypt,ruo91/letsencrypt,solidgoldbomb/letsencrypt,jmhodges/letsencrypt,hlieberman/letsencrypt,piru/letsencrypt,martindale/letsencrypt,hlieberman/letsencrypt,g1franc/lets-encrypt-preview,rutsky/letsencrypt,rutsky/letsencrypt,BillKeenan/lets-encrypt-preview,ruo91/letsencrypt,letsencrypt/letsencrypt,thanatos/lets-encrypt-preview,luorenjin/letsencrypt,stewnorriss/letsencrypt,DavidGarciaCat/letsencrypt,twstrike/le_for_patching,mrb/letsencrypt,BillKeenan/lets-encrypt-preview,kuba/letsencrypt,VladimirTyrin/letsencrypt,TheBoegl/letsencrypt,bestwpw/letsencrypt,stweil/letsencrypt,digideskio/lets-encrypt-preview,digideskio/lets-encrypt-preview,PeterMosmans/letsencrypt,bsmr-misc-forks/letsencrypt,skynet/letsencrypt,jsha/letsencrypt,deserted/letsencrypt,jmaurice/letsencrypt,rlustin/letsencrypt,Bachmann1234/letsencrypt,DavidGarciaCat/letsencrypt,mitnk/letsencrypt,hsduk/lets-encrypt-preview,sjerdo/letsencrypt,TheBoegl/letsencrypt,BKreisel/letsencrypt,BKreisel/letsencrypt,rugk/letsencrypt,fmarier/letsencrypt,sapics/letsencrypt,armersong/letsencrypt,vcavallo/letsencrypt,kevinlondon/letsencrypt,ahojjati/letsencrypt,luorenjin/letsencrypt,lmcro/letsencrypt,goofwear/letsencrypt,g1franc/lets-encrypt-preview,tdfischer/lets-encrypt-preview,ahojjati/letsencrypt,kevinlondon/letsencrypt,rugk/letsencrypt,Jonadabe/letsencrypt,tdfischer/lets-encrypt-preview,mrb/letsencrypt,sjerdo/letsencrypt,brentdax/letsencrypt,vcavallo/letsencrypt,solidgoldbomb/letsencrypt,bsmr-misc-forks/letsencrypt,riseofthetigers/letsencrypt,ghyde/letsencrypt,skynet/letsencrypt