convert wespeaker models to sherpa-onnx (#475)

scripts/wespeaker/README.md

@@ -0,0 +1,10 @@
+# Introduction
+
+This folder contains script for adding meta data to onnx models from
+https://github.com/wenet-e2e/wespeaker/blob/master/docs/pretrained.md
+
+You can use the models with metadata in sherpa-onnx.
+
+
+**Caution**: You have to add model meta data to `*.onnx` since we plan
+to support models from different frameworks.