This feature is available in Contao 4.8 and later.
Contao uses the concept of Data Container Arrays. The configuration of each data container can be adjusted and extended by yourself within your Contao application as well as by extensions. During development of a website it might be helpful to analyze the final state of a DCA - after all the adjustments have been merged together.
This command takes the name of a data container, e.g. tl_page, and outputs its final configuration to the console.
php vendor/bin/contao-console debug:dca tl_page