fix: parse ::directives correctly (#41186)

tools/challenge-parser/parser/__fixtures__/with-directives.md

@@ -0,0 +1,17 @@
+# --description--
+
+:root appears, :import appears
+
+the next paragraph should appear
+
+::import
+
+even though it's an import directive, but if we use the full syntax `::directive-name{attr="name" attr2="a/path"}`
+
+::import{component="name" from="script.md"}
+
+it goes.
+
+::: name [inline-content] {key=val}
+a container directive
+:::