Make sg installation first step in onboarding docs
Created by: mrnugget
This does two things:
- Changes the install method for
sg
from running./dev/sg/install.sh
and compiling it to the one-liner that downloads the binary and installs it. That can already solve issues for new colleagues. - It moves the
sg
to the front of the onboarding steps. That allows us to then gradually work towards https://github.com/sourcegraph/sourcegraph/issues/24900 by replacing the following steps withsg
commands.