Fix changelog formatting bug

A proper Markdown list wasn't used in the last set of changelog changes.

CHANGELOG.md

@@ -1,14 +1,14 @@
 ## **6.13.1**
-[Fix] `stringify`: avoid a crash when a `filter` key is `null`
-[Fix] `utils.merge`: functions should not be stringified into keys
-[Fix] `parse`: avoid a crash with interpretNumericEntities: true, comma: true, and iso charset
-[Fix] `stringify`: ensure a non-string `filter` does not crash
-[Refactor] use `__proto__` syntax instead of `Object.create` for null objects
-[Refactor] misc cleanup
-[Tests] `utils.merge`: add some coverage
-[Tests] fix a test case
-[actions] split out node 10-20, and 20+
-[Dev Deps] update `es-value-fixtures`, `mock-property`, `object-inspect`, `tape`
+- [Fix] `stringify`: avoid a crash when a `filter` key is `null`
+- [Fix] `utils.merge`: functions should not be stringified into keys
+- [Fix] `parse`: avoid a crash with interpretNumericEntities: true, comma: true, and iso charset
+- [Fix] `stringify`: ensure a non-string `filter` does not crash
+- [Refactor] use `__proto__` syntax instead of `Object.create` for null objects
+- [Refactor] misc cleanup
+- [Tests] `utils.merge`: add some coverage
+- [Tests] fix a test case
+- [actions] split out node 10-20, and 20+
+- [Dev Deps] update `es-value-fixtures`, `mock-property`, `object-inspect`, `tape`
 
 ## **6.13.0**
 - [New] `parse`: add `strictDepth` option (#511)