Upgrade all services for Traefik v2 ; clean Compose files ; update doc

pica-plume/docker-compose.yml

@@ -11,7 +11,7 @@ volumes:
     name: plume_first_launch
 
 networks:
-  docker_default:
+  proxy:
     external: true
   plume:
     name: plume
@@ -34,12 +34,13 @@ services:
       - searchidx:/app/search_index
       - first-launch:/firstlaunch
     labels:
-      traefik.frontend.rule: "Host:blog.picasoft.net"
+      traefik.http.routers.blog.entrypoints: websecure
+      traefik.http.routers.blog.rule: Host(`blog.picasoft.net`)
+      traefik.http.services.blog.loadbalancer.server.port: 7878
       traefik.enable: true
-      traefik.port: 7878
     networks:
       - plume
-      - docker_default
+      - proxy
     depends_on:
       - blog-db
     restart: unless-stopped