Update v2-1.md

website/docs/usage/v2-1.md

@@ -227,6 +227,11 @@ if all of your models are up to date, you can run the
   + sentence_splitter = nlp.create_pipe("sentencizer")
   ```
 
+- The keyword argument `n_threads` on the `.pipe` methods is now deprecated, as
+  the v2.x models cannot release the global interpreter lock. (Future versions
+  may introduce a `n_process` argument for parallel inference via
+  multiprocessing.)
+
 - The `Doc.print_tree` method is now deprecated. If you need a custom nested
   JSON representation of a `Doc` object, you might want to write your own helper
   function. For a simple and consistent JSON representation of the `Doc` object