[WebGPU] Add list of available features to GPUSupportedFeatures page

[chrisdavidmills]

Looking back on the documentation, it seems a bit weird that we don't document the list of the available features at https://developer.mozilla.org/en-US/docs/Web/API/GPUSupportedFeatures#available_features. We should add a list, in a similar way to the list on https://developer.mozilla.org/en-US/docs/Web/API/GPUSupportedLimits.

Acceptance criteria

• Add list of features to https://developer.mozilla.org/en-US/docs/Web/API/GPUSupportedFeatures#available_features (see https://gpuweb.github.io/gpuweb/#feature-index)
• Add support data for each of the features to BCD (GPUSupportedFeatures). Some research is needed to figure out when support for each was added...
• Saying that, support for the "timestamp-query" feature was added in Chrome 121: see https://developer.chrome.com/blog/new-in-webgpu-121#timestamp_queries_in_compute_and_render_passes.

Features that will be largely handled in separate PRs:

• [WebGPU] Add support for 16-bit floating-point values ("shader-f16" feature) in WGSL #36359 ("shader-f16" supported as of Chrome 120).
• [WebGPU] Add support for filterable 32-bit float textures ("float32-filterable" feature) #36371 ("float32-filterable" supported as of Chrome 119).
• [WebGPU] Add support for dual-source blending ("dual-source-blending" feature) in WGSL #36394 ("dual-source-blending" supported as of Chrome 130)

[chrisdavidmills]

Content PR: #36398