Add suport for ECSDA SSL certs

AdamM

What is ECDSA?

The algorithm, called ECDSA (Elliptic Curve Digital Signature Algorithm), was first proposed by Scott Vanstone in 1992. Signatures based on the algorithm of ECS, the ancestor of ECDSA, have several important advantages over RSA-algorithms: they are smaller in size and are created much faster. Verification based on ECC algorithm is high-speed, which led to widespread distribution of ECDSA certificates.
Advantages of using ECDSA to RSA

Using ECDSA for digital signature carries a number of important advantages, such as:

a high level of security;

no problems with application performance;

quick process of signing and verification (40% faster than RSA);

execution of the growing application security requirements;

support of government standards for the protection of information;

compliance with the modern requirements of industry.

Certificates with ECDSA can reduce the total amount of data to be authenticated, resulting in significant cost savings associated with date storage.

https://sectigostore.com/blog/ecdsa-vs-rsa-everything-you-need-to-know/

nhybgtvfr

+1
it's already recommended to phase out rsa2048 and replace it with ECDSA p-256 or p-384

and both certbot and acme.sh already support getting ecdsa certs with the options
--key-type ecdsa --elliptic-curve secp256r1 (or secp384r1) for certbot
or -keylength ec-256 (or ec-384) for acme.sh

so this should be something enhance can make default with minimal effort.