Add ktx

ktx/vcpkg-triplets/README.md

@@ -0,0 +1,12 @@
+<!-- Copyright 2024, The Khronos Group Inc. -->
+<!-- SPDX-License-Identifier: Apache-2.0 -->
+
+vcpkg Triplets
+==============
+
+These are necessary to get vcpkg to build the dependencies with the same
+deployment target as the KTX applications and library. When changing either
+deployment target in `../CMakeLists.txt` you must make the same change to the
+`*ios*` or `*osx*` files here.
+
+See https://github.com/microsoft/vcpkg/issues/39981.