Update 'README.md'

more readable docker run command

README.md

@@ -39,7 +39,10 @@ $ open -a XQuartz
 $ ip=$(ifconfig en0 | grep inet | awk '$1=="inet" {print $2}')
 $ xhost + $ip
 192.xxx.x.xx being added to access control list
-$ docker run --rm -it -v`pwd`:/mnt -e DISPLAY=$ip:0 -v /tmp/.X11-unix:/tmp/.X11-unix gmarxcc/texstudio:0.16
+$ docker run --rm -it -v`pwd`:/mnt \
+            -e DISPLAY=$ip:0 \
+            -v /tmp/.X11-unix:/tmp/.X11-unix \
+            gmarxcc/texstudio:0.16
 root@d442a76cd169:/# 
 ```