Syntax highlighting in README

Author: dolfandringa

README.md

@@ -1,6 +1,10 @@
 # Python nose2 unittesting example
 This is an example package setup for having unittests in a separate folder from the actual package.
 
-Run the unittests from the top folder with `PYTHONPATH=. nose2` if you haven't installed this package in your pythonpath anywhere (through virtualenv or side wide).
+Run the unittests from the top folder with:
+```bash
+PYTHONPATH=. nose2
+``` 
+if you haven't installed this package in your pythonpath anywhere (through virtualenv or side wide).
 
 Note now I modify the PYTHONPATH environment variable to tell nose2 where to find the package. I also use relative imports inside my package to make sure all modules can be found.