update changelog

Author: vincentsarago

CHANGELOG.txt

@@ -8,6 +8,8 @@
 - Enforce required `type` key for `Collection` and `Catalog` models
 - Add queryables link relation type (#123, @constantinius)
 - Fix STAC API Query Extension operator names from ne->neq, le->lte, and ge->gte (#120, @philvarner)
+- Better **datetime** parsing/validation by using Pydantic native types and remove `ciso8601` requirement (#131, @eseglem)
+- move datetime validation in `StacCommonMetadata` model definition (#131, @eseglem)
 
 3.0.0 (2024-01-25)
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