update changelog with recent changes that were merged

docs/changelog.rst

@@ -10,6 +10,7 @@ Development
 - EnumField improvements: now `choices` limits the values of an enum to allow
 - Fix deepcopy of EmbeddedDocument #2202
 - Fix error when using precision=0 with DecimalField #2535
+- Add support for regex and whole word text search query #2568
 
 Changes in 0.23.1
 ===========

mongoengine/fields.py

@@ -162,10 +162,10 @@ class StringField(BaseField):
             elif op == "regex":
                 regex = value
 
-            # escape unsafe characters which could lead to a re.error
             if op == "regex":
                 value = re.compile(regex, flags)
             else:
+                # escape unsafe characters which could lead to a re.error
                 value = re.escape(value)
                 value = re.compile(regex % value, flags)
         return super().prepare_query_value(op, value)