Arrange example configurations by vendor

.../example_configurations/AlephObjects/TAZ4/Configuration.h

...mple_configurations/AlephObjects/TAZ4/Configuration_adv.h

.../example_configurations/AliExpress/CL-260/Configuration.h

Marlin/example_configurations/AliExpress/CL-260/README.txt

Marlin/example_configurations/BQ/Hephestos/Configuration.h

...n/example_configurations/BQ/Hephestos/Configuration_adv.h

Marlin/example_configurations/BQ/Hephestos_2/Configuration.h

...example_configurations/BQ/Hephestos_2/Configuration_adv.h

Marlin/example_configurations/BQ/Hephestos_2/README.md

Marlin/example_configurations/BQ/Hephestos_2/_Bootscreen.h

Marlin/example_configurations/BQ/WITBOX/Configuration.h

Marlin/example_configurations/BQ/WITBOX/Configuration_adv.h

...xample_configurations/Folger Tech/i3-2020/Configuration.h

...le_configurations/Folger Tech/i3-2020/Configuration_adv.h

...n/example_configurations/Infitary/i3-M508/Configuration.h

...ample_configurations/Infitary/i3-M508/Configuration_adv.h

Marlin/example_configurations/Malyan/M150/Configuration.h

...in/example_configurations/Malyan/M150/Configuration_adv.h

Marlin/example_configurations/Malyan/M150/README.md

Marlin/example_configurations/Malyan/M150/_Bootscreen.h