update README.md
update README.md

- added info about open files limit
- simple load balancing with haproxy
ambrish123456/testSlanger,amvse/slanger,notnoopci/slanger,carlos-ramos-mojix-com/slanger,markburns/slanger,carlos-ramos-mojix-com/slanger,daande/slanger,loggator/slanger,daande/slanger,shaicoleman/slanger,markburns/slanger,notnoopci/slanger,stevegraham/slanger,amvse/slanger,stevegraham/slanger,loggator/slanger,ambrish123456/testSlanger,shaicoleman/slanger