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 from https://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 showing php 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 up marking_store (which you would not, if you are copying yaml example from https://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 because marking is the default field for marking store, but that's only noted in small tip on https://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