chore: update changelog.md

Signed-off-by: Manish Dait <daitmanish88@gmail.com>

Author: manishdait

CHANGELOG.md

@@ -31,6 +31,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Added `examples/token_create_transaction_token_fee_schedule.py` to demonstrate creating tokens with custom fee schedules and the consequences of not having it.
 - Added `examples/token_create_transaction_wipe_key.py` to demonstrate token wiping and the role of the wipe key.
 - Added `examples/account_allowance_approve_transaction_hbar.py` and `examples/account_allowance_delete_transaction_hbar.py`, deleted `examples/account_allowance_hbar.py`. [#775]
+- Add support for chunk message  in `TopicSubmitMessageTransaction`.
 
 
 ### Changed