[DOCKER] Update configuration script to include the worker container

docker/worker/docker-compose.fragment.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/sh
+
+if [ "${BUILD_PHP}" -ne 0 ]; then
+    cat <<EOF
+    worker:
+        build: docker/php
+EOF
+else
+    cat <<EOF
+    worker:
+        image: gsocial/php
+EOF
+fi
+
+# If the user wants a DB docker container
+if echo "${DOCKER}" | grep -Fvq '"db"'; then
+    cat <<EOF
+        depends_on:
+            - db
+EOF
+fi
+
+cat <<EOF
+        restart: always
+        tty: true
+        volumes:
+            # Entrypoint
+            - ./docker/php/entrypoint.sh:/entrypoint.sh
+            - ./docker/db/wait_for_db.sh:/wait_for_db.sh
+            - ./docker/social/install.sh:/var/entrypoint.d/social_install.sh
+            - ./docker/worker/worker.sh:/var/entrypoint.d/social_worker.sh
+            # Main files
+            - .:/var/www/social
+            - /var/www/social/docker # exclude docker folder
+        env_file:
+            - ./docker/social/social.env
+            - ./docker/db/db.env
+        command: /entrypoint.sh
+
+EOF