doc: embed example docker-compose in readme

README.md

@@ -9,7 +9,7 @@ Docker image for Mantis Bug Tracker https://www.mantisbt.org/
 
 There are some other alternative images exist already such as [vimagick/mantisbt](https://hub.docker.com/r/vimagick/mantisbt/), [xlrl/docker-mantisbt](https://github.com/xlrl/docker-mantisbt) and a few others. Why do we need yet another image?
 
-The reason is to combine all the nice features each of them have and add some missing features. To list some:
+The reason is to combine all the useful features they have and add some missing ones. To list some:
 
 - Always latest MantisBT version.
 - Comes with the latest PHP version (7.4 as for today)
@@ -34,6 +34,48 @@ https://www.mantisbt.org/docs/master/en-US/Admin_Guide/html-desktop/#admin.confi
 
 For further details refer to [official documentation](https://www.mantisbt.org/docs/master/en-US/Admin_Guide/html-desktop/#admin.install.new)
 
+# Example docker-compose.yml
+
+```YAML
+version: "3"
+
+services:
+  web:
+    # Pin the version for production usage!
+    image: okainov/mantisbt:latest
+    container_name: mantis_web
+    ports:
+      - "8989:80"
+    environment:
+      - MANTIS_ENABLE_ADMIN=1
+      # Set master salt, typically can be generated by `cat /dev/urandom | head -c 64 | base64`
+      #- MASTER_SALT=
+      # Set base email settings. For more detailed configuration (i.e. SMTP) you'll need to add own config file
+      - EMAIL_WEBMASTER=webmaster@localhost
+      - EMAIL_FROM=webmaster@localhost
+      - EMAIL_RETURN_PATH=webmaster@localhost
+      # Uncomment only if modified from default values
+      #- MYSQL_HOST=db
+      #- MYSQL_DATABASE=bugtracker
+      #- MYSQL_USER=mantis
+      #- MYSQL_PASSWORD=mantis
+    depends_on:
+      - db
+    restart: always
+
+  db:
+    image: mysql:5.7
+    container_name: mantis_db
+    volumes:
+      - ./db_data:/var/lib/mysql
+    environment:
+      - MYSQL_ROOT_PASSWORD=root
+      - MYSQL_DATABASE=bugtracker
+      - MYSQL_USER=mantis
+      - MYSQL_PASSWORD=mantis
+    command: ['mysqld', '--character-set-server=utf8mb4', '--collation-server=utf8mb4_unicode_ci']
+
+```
 
 # Extensions