As a new user I was excited by grav and how simple it all seemed until I came to this line in the instructions:
"Download the latest-and-greatest Grav or Grav + Admin package."
You're asking me, who knows nothing about Grav to make a decision on the very first step and don't provide any guidance over why I would want one over the other.
IMHO you should take a page out of django's book and just include the admin by default (i.e., make the package with the admin the default) and make a second core package for advanced users who don't want the admin. Then the step one instruction is install this one package.