update doc

docs/velox-backend-limitations.md

@@ -11,11 +11,6 @@ Gluten avoids to modify Spark's existing code and use Spark APIs if possible. Ho
 
 So you need to ensure preferentially load the Gluten jar to overwrite the jar of vanilla spark. Refer to [How to prioritize loading Gluten jars in Spark](https://github.com/oap-project/gluten/blob/main/docs/velox-backend-troubleshooting.md#incompatible-class-error-when-using-native-writer).
 
-
-### Runtime BloomFilter
-
-Velox BloomFilter's serialization format is different from Spark's. BloomFilter binary generated by Velox can't be deserialized by vanilla spark. So if `might_contain` falls back, we fall back `bloom_filter_agg` to vanilla spark also.
-
 ### Fallbacks
 Except the unsupported operators, functions, file formats, data sources listed in , there are some known cases also fall back to Vanilla Spark. 
 
@@ -29,6 +24,9 @@ Gluten only supports spark default case-insensitive mode. If case-sensitive mode
 In velox, lookaround (lookahead/lookbehind) pattern is not supported in RE2-based implementations for Spark functions,
 such as `rlike`, `regexp_extract`, etc.
 
+#### Runtime BloomFilter
+Velox BloomFilter's serialization format is different from Spark's. BloomFilter binary generated by Velox can't be deserialized by vanilla spark. So if `might_contain` falls back, we fall back `bloom_filter_agg` to vanilla spark also.
+
 #### FileSource format
 Currently, Gluten only fully supports parquet file format and partially support ORC. If other format is used, scan operator falls back to vanilla spark.