Add preloading for responsive images feature (#1076)

This is a Baseline 2023 feature.

Author: ddbeck

features/preloading-responsive-images.dist.yml

@@ -0,0 +1,22 @@
+# Generated from: preloading-responsive-images.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+name: Preloading responsive images
+description: The `imagesrcset` and `imagesizes` attributes with the `rel="preload"` attribute for the `<link>` HTML element starts fetching responsive images before they're found in the body of the document.
+spec: https://html.spec.whatwg.org/multipage/semantics.html#attr-link-imagesrcset
+status:
+  baseline: low
+  baseline_low_date: 2023-12-11
+  support:
+    chrome: "73"
+    chrome_android: "73"
+    edge: "79"
+    firefox: "78"
+    firefox_android: "79"
+    safari: "17.2"
+    safari_ios: "17.2"
+compat_features:
+  - api.HTMLLinkElement.imageSizes
+  - api.HTMLLinkElement.imageSrcset
+  - html.elements.link.imagesizes
+  - html.elements.link.imagesrcset

features/preloading-responsive-images.yml

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+name: Preloading responsive images
+description: The `imagesrcset` and `imagesizes` attributes with the `rel="preload"` attribute for the `<link>` HTML element starts fetching responsive images before they're found in the body of the document.
+spec: https://html.spec.whatwg.org/multipage/semantics.html#attr-link-imagesrcset
+compat_features:
+  - api.HTMLLinkElement.imageSizes
+  - api.HTMLLinkElement.imageSrcset
+  - html.elements.link.imagesizes
+  - html.elements.link.imagesrcset