Add HTTP/2 notes to README
Add HTTP/2 notes to README

jvandijk/epwp-trellis,all9lives/trellis,buluma/trellis,NicBeltramelli/trellis,NicBeltramelli/trellis,ChilliCreative/trellis,jeffstieler/bedrock-ansible,buluma/trellis,cimocimocimo/cimo-wordpress-server,partounian/trellis,Twansparant/trellis-db-sync,roots/bedrock-ansible,all9lives/trellis,fullyint/trellis,roots/bedrock-ansible,roots/trellis,proteusthemes/pt-ops,partounian/trellis,ckovey/trellis,ckovey/trellis,mAAdhaTTah/bedrock-ansible,dboune/trellis,partounian/trellis,BrandonShutter/trellis,kalenjohnson/trellis,ChilliCreative/trellis,mAAdhaTTah/bedrock-ansible,newtonne/trellis,dailysecret/trellis,jvandijk/epwp-trellis,kalenjohnson/trellis,Twansparant/trellis-db-sync,jeffstieler/bedrock-ansible,erikbelusic/trellis,mAAdhaTTah/bedrock-ansible,dboune/trellis,cimocimocimo/cimo-wordpress-server,jeffstieler/bedrock-ansible,kalenjohnson/trellis,partounian/trellis,Twansparant/trellis-db-sync,cimocimocimo/cimo-wordpress-server,mlaa/trellis,BrandonShutter/trellis,alan-c/trellis,buluma/trellis,fullyint/trellis,fullyint/trellis,pressbooks/trellis,alan-c/trellis,newtonne/trellis,Twansparant/trellis-db-sync,mlaa/trellis,proteusthemes/pt-ops,kalenjohnson/trellis,roots/trellis,proteusthemes/pt-ops,pressbooks/trellis,NicBeltramelli/trellis,buluma/trellis,cimocimocimo/cimo-wordpress-server,mAAdhaTTah/bedrock-ansible,dailysecret/trellis,NicBeltramelli/trellis,newtonne/trellis,fullyint/trellis,louim/bedrock-ansible