Vulkan: Document how to turn on debug markers
Vulkan: Document how to turn on debug markers

Bug: b/170249632
Change-Id: Ie71a2e9699c3da88dd7e285177bb0ce1520f5bbc
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2506420
Commit-Queue: Ian Elliott <ac50c12f27752fd82643b0b72adab33538bb2c97@google.com>
Reviewed-by: Tim Van Patten <c7814369a8d3d5671c484acc7b3215f1bf4221be@google.com>
Reviewed-by: Cody Northrop <94770d7fe1cce6ea0791fa9927c1107de4d2e37b@google.com>

ppy/angle,ppy/angle,ppy/angle,ppy/angle