命令：
# 生成Key
ssh-keygen -t ed25519 -C "你的邮箱"
# 读取公钥
cat ~/.ssh/id_ed25519.pub
使用案例：
# ssh-keygen -t ed25519 -C "你的邮箱" ##执行命令
Generating public/private ed25519 key pair.
Enter file in which to save the key (/root/.ssh/id_ed25519): ##回车
Enter passphrase (empty for no passphrase): ##回车
Enter same passphrase again: ##回车
Your identification has been saved in /root/.ssh/id_ed25519
Your public key has been saved in /root/.ssh/id_ed25519.pub
The key fingerprint is:
SHA256:xxxxxxxxxxxxxxxxxxxxk 你的邮箱
The key's randomart image is:
+--[ED25519 256]--+
| ............|
| ............|
| ............|
| ............|
| ............|
| ............|
| ............|
| ............|
| ............|
+----[SHA256]-----+
# cat ~/.ssh/id_ed25519.pub ##读取公钥，复制到github中即可。
ssh-ed25519 公钥 你的邮箱