comment: return error on constructor

Blocked by https://github.com/lightpanda-io/browsercore/issues/102

src/dom/comment.zig

@@ -20,8 +20,19 @@ const parser = @import("../netsurf.zig");
 
 const CharacterData = @import("character_data.zig").CharacterData;
 
+// https://dom.spec.whatwg.org/#interface-comment
 pub const Comment = struct {
     pub const Self = parser.Comment;
     pub const prototype = *CharacterData;
     pub const mem_guarantied = true;
+
+    // TODO add constructor, but I need to associate the new Comment
+    // with the current document global object...
+    // > The new Comment(data) constructor steps are to set this’s data to data
+    // > and this’s node document to current global object’s associated
+    // > Document.
+    // https://dom.spec.whatwg.org/#dom-comment-comment
+    pub fn constructor() !*parser.Comment {
+        return error.NotImplemented;
+    }
 };