Named PEMs

Define certificates once and reference throughout configuration.

# From file
- pem: my-cert
  path: /path/to/certificate.pem

# Inline data
- pem: my-key
  data: |
    -----BEGIN PRIVATE KEY-----
    ...
    -----END PRIVATE KEY-----

# Reference in config
- address: "0.0.0.0:443"
  protocol:
    type: tls
    tls_targets:
      "example.com":
        cert: my-cert          # Reference by name
        key: my-key
        protocol:
          type: http