Hi Sitepoint team, this issue with the documentation isn't resolved yet. I downloaded a fresh version of the Sitepoint Electrician theme this October 2017. The file "SitePoint-Electrician-Theme-Documentation-v1.pdf" that came in the zip has the old instructions on page 9. "2. Write "contact-modal" (without the quotation marks) in the URL field."
Then I looked at the .txt instructions and they are updated. In readme.txt: "2. Write "#contact-modal" (without the quotation marks) in the URL field."