Minor modifications

README.md

@@ -125,6 +125,11 @@ to specify the level of quality you desire, such as:
 
 `data = load_dataset("GEM/opusparcus", lang="fr", quality=90)`
 
+The entries in the training sets have been ranked automatically by how
+likely they are paraphrases, best first, worst last. The quality
+parameter indicates the estimated proportion (in percent) of true
+paraphrases in the set. Allowed quality values range between 60 and
+100, in increments of 5 (60, 65, 70, ... 100).
 
 
 ### Data Instances