[RFC] [DX] Profiler/WDT must/should be more documented

[94noni]

The Symfony Profiler/WDT is a great tool that must/should be more documented for developers (mostly newcomers)

Maybe here or maybe directly in the related feature's book entry

• talk about new added features (form, dump, translation, ajax) since last LTS 2.3
• replace old screenshots showing the WDT on the doc (when 2.7 LTS will be released) (cf)

[javiereguiluz]

Closing as fixed. Screenshots are updated and new docs have been added, including the WebProfilerBundle config options. See #8221.