made the mariadb example a bit more complete

README.md

@@ -40,7 +40,31 @@ during US daytime hours.
 Docker
 ------
 
-`docker pull davidsiaw/sync:3.0`
+Example for using the dockerfile on this repo.
+
+```
+docker build -t sync .
+docker network create sync
+
+docker run -d --name sync-db \
+-e MARIADB_ROOT_PASSWORD='abcdefg123456' \
+-e MARIADB_DATABASE=cytube \
+-e MARIADB_USER=cytube \
+-e MARIADB_PASSWORD=aaaaa \
+--network sync mariadb
+
+docker run -d --name sync-web \
+-e MYSQL_HOST=sync-db \
+-e MYSQL_PASSWORD=aaaaa \
+-e ROOT_URL=https://cytube.my.domain \
+-e IO_ROOT_URL=https://cytube.my.domain \
+-e ROOT_DOMAIN=cytube.my.domain \
+-e VIRTUAL_HOST=cytube.my.domain \
+-e VIRTUAL_PORT=8080 \
+-e LETSENCRYPT_HOST=cytube.my.domain \
+-e YOUTUBE_KEY=abcdefg \
+--network sync sync
+```
 
 Feedback
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