updated the verbiage on the contribution page to match the site
updated the verbiage on the contribution page to match the site

pjdufour/project-open-data.github.io,pjdufour/project-open-data.github.io,portofsandiego/project-open-data.github.io,pjdufour/project-open-data.github.io,pjdufour/project-open-data.github.io,portofsandiego/project-open-data.github.io,portofsandiego/project-open-data.github.io,portofsandiego/project-open-data.github.io