fixing up description for @chrisfilo!

Author: vsoch

README.md

@@ -27,7 +27,7 @@ Replace `D:\host\path\where\to\output\singularity\image` with a path on the host
 ### Contributed Examples
 The following are a list of brief examples and tutorials generated by the Singularity community for using **docker2singularity**. If you have an example of your own, please [let us know](https://www.github.com/singularityware/docker2singularity/issues)!
 
- - [docker2singularity-demo](https://github.com/stevekm/docker2singularity-demo): an example of using docker2singularity on MacOS using Vagrant, complete with notes and a nice Makefile
+ - [docker2singularity-demo](https://github.com/stevekm/docker2singularity-demo): an example of using docker2singularity on MacOS and using Vagrant to test the output Singularity image, complete with notes and a nice Makefile.
 
 
 ## Tips for making Docker images compatible with Singularity