Update README.md

Updated description

README.md

@@ -1,3 +1,11 @@
----
-license: cc-by-4.0
----
+---
+description: >
+  This dataset was created from the Turkish Wikipedia dump available at
+  https://dumps.wikimedia.org/trwiki/latest/. The data was processed using an
+  annotator model, which added the metadata fields `len_data`, `topic`, and
+  `quality_score` to each entry. All entries with a `len_data` (character count)
+  value below 50 were removed.
+license: cc-by-4.0
+language:
+- tr
+---