Fix grep examples in README.md
Fix grep examples in README.md

bheuvel/chefspec,coderanger/chefspec,h4ck3rm1k3/chefspec,gsavage/chefspec,shanethehat/chefspec,375gnu/chefspec,gsavage/chefspec,lamont-granquist/chefspec,jkeiser/chefspec,mcoolive/chefspec,chefspec/chefspec,bheuvel/chefspec,ranjib/chefspec,Thalagyrt/chefspec,sethvargo/chefspec,mcoolive/chefspec,sethvargo/chefspec,coderanger/chefspec,jtimberman/chefspec,jkeiser/chefspec,oldirty/chefspec,rsr5/chefspec,lamont-granquist/chefspec,375gnu/chefspec,shanethehat/chefspec,oldirty/chefspec,aspiers/chefspec,Thalagyrt/chefspec,jtimberman/chefspec,rsr5/chefspec,h4ck3rm1k3/chefspec,aspiers/chefspec,chefspec/chefspec,ranjib/chefspec