Expose the Default Traefik Log Level variable

Instead of hiding it in the documentation and in the
docker-compose.acme.yml and docker-compose.traefik.yml files, adding it
to the sample.env file

build/docker-compose/docker-compose.acme.yml

@@ -17,7 +17,7 @@ services:
       - --entryPoints.activemq.address=:8161
       - --entryPoints.solr.address=:8983
       - --entryPoints.code-server.address=:8443
-      - --log.level=${TRAEFIK_LOG_LEVEL-ERROR}
+      - --log.level=${TRAEFIK_LOG_LEVEL:-ERROR}
       - --providers.docker
       - --providers.docker.network=gateway
       - --providers.docker.exposedByDefault=false

sample.env

@@ -35,6 +35,7 @@ PROJECT_DRUPAL_DOCKERFILE=Dockerfile
 # Includes `traefik` as a service, if false assume we are sharing a traefik
 # from another project.
 INCLUDE_TRAEFIK_SERVICE=true
+TRAEFIK_LOG_LEVEL=ERROR
 
 # Should we use ACME to generate a SSL Certificate
 USE_ACME=false