fixup! docs: document TestScope APIs

Author: ErichDonGubler

moz-webgpu-cts/src/shared.rs

@@ -734,6 +734,7 @@ impl From<FirefoxTestScope> for TestScope {
 /// Subset of [`TestScope`] for [`Browser::Servo`].
 #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub(crate) enum ServoTestScope {
+    /// A WebGPU CTS test vendored into Servo source.
     WebGpu,
 }