Add the command to install opensl dev prompt in the setup section

[mimuyi]

Where in the docs did you come across this?

setup cargo-generate

Describe what about it does not make sense

If there is no openssl dev, an error will be prompted

Why does it not make sense?

How could we improve it?

Ubuntu/Debian:
sudo apt-get install libssl-dev pkg-config

Fedora/RHEL/CentOS:
sudo dnf/yum install openssl-devel

Arch Linux:
sudo pacman -S openssl pkgconf

macOS (Homebrew):
brew install openssl@3