Hi,

I would like to mark couple of ideas to improve Workflow component documentation

1. Main page:https://symfony.com/doc/current/workflow.html
   This page is currently only showing information about what workflow is and not what it is in Symfony - I think we could move here information fromhttps://symfony.com/doc/current/workflow/usage.html (beside events part probably, which could go to separate page)

2. I think we could better show on main page difference between workflow and state machine - when you would like to use one or other. Maybe an additional example of state machine beside the link to "Workflow as state machine"?

3. Better way of showingphp bin/console workflow:dump - currently to see this extremely helpful command, I need to go to the bottom of "How to dump workflows" page - I think we could add some information on that right after the configuration examples?

4. Currently when you would not set upmarking_store (which you would not, if you are copying yaml example fromhttps://symfony.com/doc/current/workflow/state-machines.html like I did) you are getting following exception:
   An exception has been thrown during the rendering of a template ("Neither the property "marking" nor one of the methods "getMarking()", "marking()", "isMarking()", "hasMarking()", "__get()" exist and have public access in class "App\Entity\Task".").
   That is becausemarking is the default field for marking store, but that's only noted in small tip onhttps://symfony.com/doc/current/workflow/usage.html.
   Not sure if this is a documentation issue or we can improve DX in a code itself to show better exception message?

Let me know what you think - I would be more than happy to start WIP pull request for above changes.
#SymfonyConHackDay2018