Update duckdb index files

.gitattributes

@@ -56,3 +56,4 @@ data/train.json filter=lfs diff=lfs merge=lfs -text
 data/test.json filter=lfs diff=lfs merge=lfs -text
 policies-qa-training.json filter=lfs diff=lfs merge=lfs -text
 plain_text/test/index.duckdb filter=lfs diff=lfs merge=lfs -text
+plain_text/train/index.duckdb filter=lfs diff=lfs merge=lfs -text

plain_text/train/index.duckdb

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:15db756600a2d729448f265d32bea342c89729df1aec801536f20e2836c99431
+size 3944448