How to convert ed25519 private key from der to pem?

[Glen Huang]

NVM, just found out it was asked sometime ago: https://www.mail-archive.com/openssl-users@openssl.org/msg86720.html

> On Nov 5, 2019, at 2:52 PM, Glen Huang <heyhgl at gmail.com> wrote:
> 
> To convert RSA private key from der to pem, I can use the rsa subcommand, but there is no ed25519, and ec doesn’t seem to work for ed25519.
> 
> I wonder if it’s possible to convert ed25519 private key from der to pem with openssl? What’s the proper way?