fix typo

Author: Panmax

README.md

@@ -3,12 +3,12 @@
 ### How to run
 
 1. `docker build -t panmax/svg2png .`
-2. `docker run -d --name svg2png --restart=always -p 5000:5000 panmax/docker-flask`
+2. `docker run -d --name svg2png --restart=always -p 5000:5000 panmax/svg2png`
 
 ### Online address
 
 [http://svg.jpanj.com/convert](http://svg.jpanj.com/convert)
 
 ![](https://s1.ax1x.com/2018/11/05/ionBwV.png)
 
-❤️
+❤️