Bring Your Own (BYO) certificates flow

[bwbroersma]

Currently certbot is always enabled (although it's using staging on dev/testing).
In the case of non-ACME certificates, or if running in an air-gapped environment it's needed to:

• remove tls_init.sh
  

  Internet.nl/docker/webserver.Dockerfile

  Line 24 in 30be0e8

  COPY docker/webserver/tls_init.sh /docker-entrypoint.d/tls_init.sh

• remove certbot.sh
  

  Internet.nl/docker/webserver.Dockerfile

  Line 18 in 30be0e8

  COPY docker/webserver/certbot.sh /docker-entrypoint.d/certbot.sh

• mount/copy certificates to the letsencrypt path
  

  Internet.nl/docker/webserver/nginx_templates/app.conf.template

  Lines 140 to 141 in 30be0e8

  	ssl_certificate /etc/letsencrypt/live/${INTERNETNL_DOMAINNAME}/fullchain.pem;
  	ssl_certificate_key /etc/letsencrypt/live/${INTERNETNL_DOMAINNAME}/privkey.pem;

Would be nice to document this, and maybe better facilitate the BYO certificates, by having a flag to disable certbot.