Links broken for reference [GLES30] and [GLES30GLSL]

[SuperSodaSea]

The reference link for [GLES30] and [GLES30GLSL] are broken and both of them went to 404:

WebGL/specs/latest/2.0/index.html

Lines 4299 to 4308 in 44a1ee1

	<dt id="refsGLES30">[GLES30]</dt>
	<dd><cite><a href="http://www.khronos.org/registry/gles/specs/3.0/es_spec_3.0.4.pdf">
	OpenGL&reg; ES Version 3.0.4</a></cite>,
	B. Lipchak 2014.
	</dd>
	<dt id="refsGLES30GLSL">[GLES30GLSL]</dt>
	<dd><cite><a href="http://www.khronos.org/registry/gles/specs/3.0/GLSL_ES_Specification_3.00.pdf">
	The OpenGL&reg; ES Shading Language Version 3.00.6</a></cite>,
	R. Simpson, January 2016.
	</dd>

The link for [GLES30GLSL] (GLSL ES 3.00.6):

http://www.khronos.org/registry/gles/specs/3.0/GLSL_ES_Specification_3.00.pdf

can be simply replaced with

https://www.khronos.org/registry/OpenGL/specs/es/3.0/GLSL_ES_Specification_3.00.pdf

now.

However the link for [GLES30]:

http://www.khronos.org/registry/gles/specs/3.0/es_spec_3.0.4.pdf

refers to GLES 3.0.4, but I can only find the latest pdf for GLES 3.0.6 on khronos' pages

https://www.khronos.org/registry/OpenGL/specs/es/3.0/es_spec_3.0.pdf

which I think cannot be replaced directly.

[lexaknyazev]

/cc @Khronoswebmaster

[KhronosWebservices]

@kenrussell are the suggested links the best ones to use?

[SuperSodaSea]

By the way, the link for reference [WEBIDL] https://heycam.github.io/webidl/ is still working but being a redirection to https://webidl.spec.whatwg.org/ .

WebGL/specs/latest/2.0/index.html

Lines 4318 to 4322 in 44a1ee1

	<dt id="refsWEBIDL">[WEBIDL]</dt>
	<dd><cite><a href="https://heycam.github.io/webidl/">
	Web IDL: W3C Editor’s Draft</a></cite>,
	C. McCormack, B. Zbarsky, T. Langel.
	</dd>

[KhronosWebservices]

Thank you @SuperSodaSea. You are welcome of course to make a PR for these link changes. We can then ask for reviews and approve if all looks good.