Update Changelog (#729)

Author: mununki

CHANGELOG.md

@@ -55,6 +55,7 @@
 - Fix build error where aliasing arguments to `_` in the make function with JSX V4. https://github.com/rescript-lang/syntax/pull/720
 - Fix parsing of spread props as an expression in JSX V4 https://github.com/rescript-lang/syntax/pull/721
 - Fix dropping attributes from props in make function in JSX V4 https://github.com/rescript-lang/syntax/pull/723
+- Fix an issue where error messages related to duplicate props were displayed without a loc and were unclear https://github.com/rescript-lang/syntax/pull/728
 
 #### :eyeglasses: Spec Compliance