docs(caddy): a few more updates

[coolaj86]

fixed a typo, moved a few sections into a better order

[coolaj86]

Don't get the dev site flagged by browser block lists as spam:

dev.example.com {

   ...

    header {
        Link "<https://production.example.com{http.request.orig_uri}>; rel=\"canonical\""
        X-Robots-Tag noindex
    }
}

[coolaj86]

Also need xcaddy and how to use tls plugins.

caddy run --envfile .env.secret --config ./Caddyfile

example.com {
    # ...
    tls {
        dns duckdns {env.DUCKDNS_API_TOKEN}
    }
}

#!/bin/sh

#export XCADDY_SETCAP=1
export XCADDY_SUDO=0
export XCADDY_SKIP_CLEANUP=1

xcaddy build \
    --with github.com/mholt/caddy-l4/layer4 \
    --with github.com/mholt/caddy-l4/modules/l4tls \
    --with github.com/mholt/caddy-l4/modules/l4subroute \
    --with github.com/mholt/caddy-l4/modules/l4http \
    --with github.com/mholt/caddy-l4/modules/l4ssh \
    --with github.com/mholt/caddy-l4/modules/l4proxy \
    --with github.com/caddy-dns/cloudflare \
    --with github.com/caddy-dns/duckdns