MacOS: restart needed after xquartz install

(issue #3)

README.md

@@ -9,16 +9,16 @@ It is based on [i386/debian:stretch-slim](https://hub.docker.com/r/i386/debian/)
 
 See https://appdb.winehq.org/objectManager.php?sClass=version&iId=32007 for more information.
 
-### Note for Mac OS X users
+### Note for macOS users
 
-Mac OS X support is still under test.
+MacOS support is still under test.
 Using [Homebrew](https://brew.sh/), install XQuartz, socat, and the GNU version of getopt:
 
 ```
 brew cask install xquartz 
 brew install socat gnu-getopt 
 ```
-Then follow the standard usage.
+Then *restart* your session and follow the standard usage.
 Please give us feedback on https://github.com/pauleve/docker-mtgo/issues/3 (being positive or negative, with the full output of the `run-mtgo` script).
 
 ## Usage