Add the referencetarget feature

features/referencetarget.yml

@@ -0,0 +1,8 @@
+name: Reference target
+description: The `referenceTarget` property of a `ShadowRoot` object forwards attributes such as `for` and `aria-labelledby` to elements inside a shadow DOM. This allows, for example, to link a `<label>` to its `<input>` even if the `<input>` is in the shadow DOM of a web component.
+spec: https://github.com/WICG/webcomponents/blob/gh-pages/proposals/reference-target-explainer.md
+group:
+  - web-components
+# No BCD keys yet as the feature hasn't shipped anywhere.
+# It's being implemented in Chromium, and has gone through an origin trial in 133-135:
+# https://chromestatus.com/feature/5188237101891584

features/referencetarget.yml.dist

@@ -0,0 +1,6 @@
+# Generated from: referencetarget.yml
+# Do not edit this file by hand. Edit the source file instead!
+
+status:
+  baseline: false
+  support: {}

scripts/specs.ts

@@ -141,6 +141,10 @@ const defaultAllowlist: allowlistItem[] = [
     [
         "https://www.w3.org/TR/2022/WD-selectors-4-20220507/#the-target-within-pseudo",
         "Allowed because this is where the feature last appeared in the spec before removal."
+    ],
+    [
+        "https://github.com/WICG/webcomponents/blob/gh-pages/proposals/reference-target-explainer.md",
+        "Allowed because the referencetarget feature isn't in a spec yet."
     ]
 ];