Minor doc change to force a new examples build

Author: stmuk

README.md

@@ -61,7 +61,7 @@ To run all examples and tests, a number of modules need to be installed.
 
 These are listed in `META6.json`.
 
-They can be installed via `zef` or `panda`:
+They can be installed via `zef` (prefered) or `panda`:
 
     $ zef --depsonly install .
     $ panda installdeps .