add doc for ascii_folding

Signed-off-by: BubbleCal <[email protected]>

python/python/lance/dataset.py

@@ -1358,6 +1358,10 @@ def create_scalar_index(
         remove_stop_words: bool, default False
             This is for the ``INVERTED`` index. If True, the index will remove
             stop words.
+        ascii_folding: bool, default False
+            This is for the ``INVERTED`` index. If True, the index will convert
+            non-ascii characters to ascii characters if possible.
+            This would remove accents like "é" -> "e".
 
         Examples
         --------

rust/lance-index/src/scalar/inverted/builder.rs

@@ -517,6 +517,7 @@ impl IndexWorker {
         Ok(())
     }
 
+    #[instrument(level = "debug", skip_all)]
     async fn flush_posting_list(&mut self, token: String) -> Result<usize> {
         if let Some(posting_list) = self.posting_lists.remove(&token) {
             let size = posting_list.size();