doc: mark KHR_parallel_shader_compile as (mostly) done.

doc/opengl-support.dox

@@ -297,7 +297,7 @@ Extension                                   | Status
 @gl_extension{KHR,blend_equation_advanced}  | done
 @gl_extension2{KHR,blend_equation_advanced_coherent,KHR_blend_equation_advanced} | done
 @gl_extension{KHR,texture_compression_astc_sliced_3d} | done (nothing to do)
-@gl_extension{KHR,parallel_shader_compile}  | |
+@gl_extension{KHR,parallel_shader_compile}  | missing thread count setting
 
 @subsection opengl-support-extensions-vendor Vendor OpenGL extensions
 
@@ -490,7 +490,7 @@ Extension                                   | Status
 @gl_extension{KHR,context_flush_control}    | |
 @gl_extension{KHR,no_error}                 | done
 @gl_extension{KHR,texture_compression_astc_sliced_3d} | done (nothing to do)
-@gl_extension{KHR,parallel_shader_compile}  | |
+@gl_extension{KHR,parallel_shader_compile}  | missing thread count setting
 @gl_extension2{NV,read_buffer_front,NV_read_buffer} | done
 @gl_extension2{NV,read_depth,NV_read_depth_stencil} | done
 @gl_extension2{NV,read_stencil,NV_read_depth_stencil} | done
@@ -566,7 +566,7 @@ Extension                                   | Status
 @webgl_extension{EXT,clip_cull_distance}    | done
 @webgl_extension{EXT,texture_norm16}        | done
 @webgl_extension{EXT,draw_buffers_indexed}  | done
-@webgl_extension{KHR,parallel_shader_compile} | |
+@webgl_extension{KHR,parallel_shader_compile} | done
 @webgl_extension{OES,texture_float_linear}  | done
 @webgl_extension{OVR,multiview2}            | |
 @webgl_extension{WEBGL,lose_context}        | |