Updated pillar example and README for new debconf mysql root password feature

README.rst

@@ -24,3 +24,5 @@ Install the MySQL client package.
 ----------------
 
 Install the MySQL server package and start the service.
+
+Debian OS family supports setting MySQL root password during install via debconf.

pillar.example

 mysql:
   server:
+    root_password: somepass
     bind-address: 127.0.0.1
     port: 3306
     user: mysql