Add to changelog

Signed-off-by: iifawzi <iifawzie@gmail.com>

Author: iifawzi

CHANGELOG.md

@@ -13,6 +13,7 @@
 * Fixed differentiating between `ANALYZE` and `EXPLAIN` statements (#386)
 * Added "NOT" to the select options (#374)
 * Implement the `EXPLAIN` Parser (#389)
+* Performance improvement to use less the `nextToken()` function (#397)
 
 ## [5.5.0] - 2021-12-08