Revise steps 9-11 in the Setup Git section of the Contributor Guide so that lines are no longer than 80 characters, the RST style is consistent with the rest of the Guide, and that a typo is corrected.
Revise steps 9-11 in the Setup Git section of the Contributor Guide so
that lines are no longer than 80 characters, the RST style is
consistent with the rest of the Guide, and that a typo is corrected.

mmessick/Tax-Calculator,jlyons871/Tax-Calculator,mcdeaton13/Tax-Calculator,mcdeaton13/Tax-Calculator,jlyons871/Tax-Calculator,mmessick/Tax-Calculator