update readme with additional include_recipe example
update readme with additional include_recipe example

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