Bugfix in the built-in prompt references definition

internal/framework/pipeline/references.go

@@ -175,6 +175,9 @@ func referenceMediaTypeForPath(path string) string {
 		if extension == ".md" || extension == ".markdown" {
 			return "text/markdown"
 		}
+		if extension == ".yaml" || extension == ".yml" {
+			return "application/yaml"
+		}
 		return unknownMediaType
 	}
 	return canonicalMediaType(mediaType)