chore(Procfile): added multiple crons example

examples/Procfile

@@ -2,6 +2,7 @@
 # web: node server.js
 # release: make PROD=1
 # static: /:public,/somepath:somedir
-# cron: */5 * * * * python batch.py
+# cron1: */5 * * * * python batch.py
+# cron2: */5 * * * * python batch.py
 # somepyworker: python somescript.py
 # somenodeworker: node somescript.js