vulkan sdk update docs

Author: Firestar99

tools/generate/vulkan-sdk-update.md

@@ -0,0 +1,6 @@
+# Vulkan sdk update
+
+1. in `.gitmodules` set branch for both submodules to the new vulkan sdk version's branch
+2. update submodules: `git submodule update --remote`
+3. regenerate generated header files, requires python: `cargo run generate`
+4. try to compile and run the tests, fixup any errors: `cargo test --all-features`