Use links to github instead of internal gitlab

Author: oddhack

proposals/VK_EXT_frame_boundary.adoc

@@ -1,5 +1,4 @@
 // Copyright 2022-2026 The Khronos Group Inc.
-//
 // SPDX-License-Identifier: CC-BY-4.0
 
 = VK_EXT_frame_boundary
@@ -12,7 +11,7 @@
 debuggers) to group queue submissions per frames in non-trivial scenarios,
 typically when `vkQueuePresentKHR` is not a relevant frame boundary delimiter.
 
-See also the discussion in https://gitlab.khronos.org/vulkan/vulkan/-/issues/2436
+Also see the discussion in internal gitlab issue 2436.
 
 == Problem Statement
 

proposals/VK_KHR_shader_constant_data.adoc

@@ -1,11 +1,11 @@
 // Copyright 2021-2026 The Khronos Group Inc.
-//
 // SPDX-License-Identifier: CC-BY-4.0
 
 = VK_KHR_shader_constant_data
 :toc: left
 :docs: https://docs.vulkan.org/spec/latest/
 :extensions: {docs}appendices/extensions.html#
+:spirvextensions: https://github.khronos.org/SPIRV-Registry/extensions/
 :sectnums:
 // Required so images render in github
 ifndef::images[:images: ../images]
@@ -14,8 +14,9 @@ This extension allows applications to specify large constant data arrays in thei
 
 == Problem Statement
 
-https://gitlab.khronos.org/spirv/spirv-extensions/-/blob/SPV_KHR_large_constants/SPV_KHR_constant_data.asciidoc[`SPV_KHR_constant_data`] added the capability to specify arrayed data as constants in SPIR-V, to enable the specification of strings as data, or other chunks of data, in a more compact manner than previously available.
-A detailed problem statement on why this was added to SPIR-V is provided in the https://gitlab.khronos.org/spirv/spirv-extensions/-/blob/SPV_KHR_large_constants/SPV_KHR_constant_data.asciidoc[`SPV_KHR_constant_data` specification].
+{spirvextensions}/KHR/SPV_KHR_constant_data.asciidoc[`SPV_KHR_constant_data`] added the capability to specify arrayed data as constants in SPIR-V, to enable the specification of strings as data, or other chunks of data, in a more compact manner than previously available.
+A detailed problem statement on why this was added to SPIR-V is provided in
+the `SPV_KHR_constant_data` specification.
 
 Support for this extension is required in Vulkan to add better string support to Vulkan, and particularly for link:{extensions}VK_KHR_shader_abort[VK_KHR_shader_abort].
 

registry.adoc

@@ -114,7 +114,7 @@ https://registry.khronos.org/vulkan/ .
 = Getting Started
 
 See
-https://gitlab.khronos.org/vulkan/vulkan/blob/main/xml/BUILD.adoc[`xml/BUILD.adoc`]
+https://github.com/KhronosGroup/Vulkan-Docs/blob/main/BUILD.adoc[`xml/BUILD.adoc`]
 in the `Vulkan-Docs` repository for information on required toolchain
 components such as Python 3, pass:[g++], and GNU make.