Update extensions registry (#2568)

Author: lexaknyazev

extensions/2.0/Khronos/KHR_node_visibility/README.md

@@ -9,7 +9,7 @@
 
 ## Status
 
-Release Candidate
+Complete, Ratified by the Khronos Group
 
 ## Dependencies
 

extensions/README.md

@@ -25,6 +25,7 @@ The following extensions have been ratified by the Khronos Group:
 * [KHR_materials_variants](2.0/Khronos/KHR_materials_variants/README.md)
 * [KHR_materials_volume](2.0/Khronos/KHR_materials_volume/README.md)
 * [KHR_mesh_quantization](2.0/Khronos/KHR_mesh_quantization/README.md)
+* [KHR_node_visibility](2.0/Khronos/KHR_node_visibility/README.md)
 * [KHR_texture_basisu](2.0/Khronos/KHR_texture_basisu/README.md)
 * [KHR_texture_transform](2.0/Khronos/KHR_texture_transform/README.md)
 * [KHR_xmp_json_ld](2.0/Khronos/KHR_xmp_json_ld/README.md)
@@ -44,12 +45,12 @@ This section tracks the status of extensions and projects that are in developmen
 | KHR_accessor_float64 | Review Draft | [PR #2397](https://github.com/KhronosGroup/glTF/pull/2397) |
 | KHR_audio_graph | Proposal | [PR #2421](https://github.com/KhronosGroup/glTF/pull/2421) |
 | KHR_collision_shapes | Review Draft | [PR #2370](https://github.com/KhronosGroup/glTF/pull/2370) |
+| KHR_gaussian_splatting | Release Candidate | [Specification](2.0/Khronos/KHR_gaussian_splatting/README.md) |
 | KHR_interactivity | Review Draft | [PR #2293](https://github.com/KhronosGroup/glTF/pull/2293) |
 | KHR_materials_diffuse_transmission | Release Candidate | [Specification](2.0/Khronos/KHR_materials_diffuse_transmission/README.md) |
 | KHR_materials_subsurface | Initial Draft | [PR #1928](https://github.com/KhronosGroup/glTF/pull/1928) |
 | KHR_node_hoverability | Review Draft | [PR #2426](https://github.com/KhronosGroup/glTF/pull/2426) |
 | KHR_node_selectability | Review Draft | [PR #2422](https://github.com/KhronosGroup/glTF/pull/2422) |
-| KHR_node_visibility | Review Draft | [PR #2410](https://github.com/KhronosGroup/glTF/pull/2410) |
 | KHR_physics_rigid_bodies | Review Draft | [PR #2424](https://github.com/KhronosGroup/glTF/pull/2424) |
 | KHR_texture_procedurals | Initial Draft | [PR #2381](https://github.com/KhronosGroup/glTF/pull/2381) |
 | EXT_texture_procedurals_mx_1_39 | Review Draft | [PR #2381](https://github.com/KhronosGroup/glTF/pull/2381) |