Follow cl-vk cb47a8c: the types of the enums' keywords
The pages on structs, the generator and the packages say that each enum's
keywords are a type of cl-vk/structs, named as the structs are, VkFormat's
being vk-format.
The requirements name SBCL alone, the platform page describes cl-vk/sys
as what cl-vk takes from SBCL, and the test commands and the generator's
reason for laying out its output by hand no longer mention CCL. The
allocation claims drop their "on SBCL".
Follows cl-vk cae101e: the raw layer's structs, types and the loader's
library are cl-ffi's, the examples use cl-ffi's operators, and getting
started lists cl-ffi in the qlfile beside cl-vk.
