Add my new, shiny module.

my_metric.py

@@ -0,0 +1,12 @@
+from evaluate import Metric
+
+class WemingMetric(Metric):
+
+    def _download_and_prepare(self, dl_manager):
+        import nltk
+        nltk.download("punkt")
+
+    def _compute(self, references, predictions):
+        em = sum([r==p for r, p in zip(references, predictions)])/len(references)
+        return {"exact_match": em}
+#test