Add GitHub signing SSH key

ssh_signing_key.sh

#!/bin/bash

# Name of SSH key
key=github_ed25519 # You can rename this

# Generate new SSH key
ssh-keygen -t ed25519 -f ~/.ssh/${key} -q -P ""

# Authorized it
cat ~/.ssh/${key}.pub >>~/.ssh/authorized_keys

# Configure ~/.gitconfig
git config --global user.signingkey "~/.ssh/${key}.pub"
git config --global gpg.format "ssh"
git config --global commit.gpgsign "true"

# Get SSH key
echo "! First copy your ssh-key:"
cat ~/.ssh/$key.pub #| clip

# Add new signing key on GitHub
echo "Open this URL to continue in your web browser: https://github.com/settings/keys"
echo "Create new SSH key. The key type must be signing key."