Fix code example typo (#521)
Fix code example typo (#521)


mingaldrichgan/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,okcoker/gatsby,danielfarrell/gatsby,fabrictech/gatsby,danielfarrell/gatsby,fk/gatsby,mickeyreiss/gatsby,ChristopherBiscardi/gatsby,0x80/gatsby,Khaledgarbaya/gatsby,chiedo/gatsby,gatsbyjs/gatsby,fk/gatsby,0x80/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,rothfels/gatsby,Khaledgarbaya/gatsby,fabrictech/gatsby,0x80/gatsby,okcoker/gatsby,mingaldrichgan/gatsby,chiedo/gatsby,mickeyreiss/gatsby,chiedo/gatsby,mingaldrichgan/gatsby,ChristopherBiscardi/gatsby,rothfels/gatsby,mickeyreiss/gatsby,Khaledgarbaya/gatsby,gatsbyjs/gatsby,danielfarrell/gatsby,fk/gatsby,fabrictech/gatsby,gatsbyjs/gatsby,okcoker/gatsby