docs: fix markdown formatting in changelog

Signed-off-by: adityashirsatrao007 <adityashirsatrao007@gmail.com>

Author: adityashirsatrao007

CHANGELOG.md

@@ -10,18 +10,18 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 
 - Modularized `transfer_transaction_fungible` example by introducing `account_balance_query()` & `transfer_transaction()`.Renamed `transfer_tokens()` → `main()`
 - Phase 2 of the inactivity-unassign bot:Automatically detects stale open pull requests (no commit activity for 21+ days), comments with a helpful InactivityBot message, closes the stale PR, and unassigns the contributor from the linked issue.
-- Added **str**() to CustomFixedFee and updated examples and tests accordingly.
+- Added `__str__()` to CustomFixedFee and updated examples and tests accordingly.
 - Added unit tests for `crypto_utils` (#993)
 - Added a github template for good first issues
 - Added `.github/workflows/bot-assignment-check.yml` to limit non-maintainers to 2 concurrent issue assignments.
-- Added all missing fields to **str**() method and updated `test_tokem_info.py`
+- Added all missing fields to `__str__()` method and updated `test_tokem_info.py`
 - Add examples/tokens/token_create_transaction_pause_key.py example demonstrating token pause/unpause behavior and pause key usage (#833)
 - Added `docs/sdk_developers/training/transaction_lifecycle.md` to explain the typical lifecycle of executing a transaction using the Hedera Python SDK.
 - Add inactivity bot workflow to unassign stale issue assignees (#952)
 - Made custom fraction fee end to end
 - feat: AccountCreateTransaction now supports both PrivateKey and PublicKey [#939](https://github.com/hiero-ledger/hiero-sdk-python/issues/939)
 - Added Acceptance Criteria section to Good First Issue template for better contributor guidance (#997)
-- Added **str**() to CustomRoyaltyFee and updated examples and tests accordingly (#986)
+- Added `__str__()` to CustomRoyaltyFee and updated examples and tests accordingly (#986)
 - Restore bug and feature request issue templates (#996)(https://github.com/hiero-ledger/hiero-sdk-python/issues/996)
 - Support selecting specific node account ID(s) for queries and transactions and added `Network._get_node()` with updated execution flow (#362)
 - Add TLS support with two-stage control (`set_transport_security()` and `set_verify_certificates()`) for encrypted connections to Hedera networks. TLS is enabled by default for hosted networks (mainnet, testnet, previewnet) and disabled for local networks (solo, localhost) (#855)