Added ACME support to features list

README.md

@@ -46,13 +46,19 @@ It's super easy to get started and to operate `step-ca` thanks to [streamlined i
 - [Instance identity documents](https://smallstep.com/blog/embarrassingly-easy-certificates-on-aws-azure-gcp/) for VMs on AWS, GCP, and Azure
 - [Single-use short-lived tokens](https://smallstep.com/docs/design-doc.html#jwk-provisioner) issued by your CD tool — Puppet, Chef, Ansible, Terraform, etc.
 - Use an existing certificate from another CA (e.g., using a device certificate like [Twilio's Trust OnBoard](https://www.twilio.com/wireless/trust-onboard)) *coming soon*
-- ACMEv2 (RFC8555) support so you can **run your own private ACME server** *[coming soon](https://github.com/smallstep/certificates/tree/acme)*
+
+### [Your own private ACME Server](https://smallstep.com/blog/private-acme-server/)
+- Issue certificates using ACMEv2 ([RFC8555](https://tools.ietf.org/html/rfc8555)), **the protocol used by Let's Encrypt**
+- Great for [using ACME in development & pre-production](https://smallstep.com/blog/private-acme-server/#local-development-pre-production)
+- Supports the `http-01` and `dns-01` ACME challenge types
+- Works with any compliant ACME client including [certbot](https://smallstep.com/blog/private-acme-server/#certbot-uploads-acme-certbot-png-certbot-example), [acme.sh](https://smallstep.com/blog/private-acme-server/#acme-sh-uploads-acme-acme-sh-png-acme-sh-example), [Caddy](https://smallstep.com/blog/private-acme-server/#caddy-uploads-acme-caddy-png-caddy-example), and [traefik](https://smallstep.com/blog/private-acme-server/#traefik-uploads-acme-traefik-png-traefik-example)
+- Get certificates programmatically (e.g., in [Go](https://smallstep.com/blog/private-acme-server/#golang-uploads-acme-golang-png-go-example), [Python](https://smallstep.com/blog/private-acme-server/#python-uploads-acme-python-png-python-example), [Node.js](https://smallstep.com/blog/private-acme-server/#node-js-uploads-acme-node-js-png-node-js-example))
 
 ### [SSH Certificates](https://smallstep.com/blog/use-ssh-certificates/)
 
-* Use [certificate authentication for SSH](https://smallstep.com/blog/use-ssh-certificates/): connect SSH to SSO, improve security, and eliminate warnings & errors
-* Issue SSH user certificates using OAuth OIDC
-* Issue SSH host certificates to cloud VMs using instance identity documents
+- Use [certificate authentication for SSH](https://smallstep.com/blog/use-ssh-certificates/): connect SSH to SSO, improve security, and eliminate warnings & errors
+- Issue SSH user certificates using OAuth OIDC
+- Issue SSH host certificates to cloud VMs using instance identity documents
 
 ### Easy certificate management and automation via [`step` CLI](https://github.com/smallstep/cli) [integration](https://smallstep.com/docs/cli/ca/)