refactor(build): update changelog formatting in gradle task (#36021)

* docs: add formatting instructions for CHANGES.md

Add documentation for the new formatChanges Gradle task that helps maintain consistent formatting in CHANGES.md. Also includes minor formatting fixes in CHANGES.md itself.

* refactor(build): update changelog formatting in gradle task

Modify the formatChanges task to standardize SDK language references in CHANGES.md by converting square brackets to parentheses for better consistency. The change specifically targets language mentions at the end of sentences or before issue references.

* formatted changes

* refactor(build): simplify blank line addition in formatChanges task

The change removes the conditional check for adding a blank line after the template in the formatChanges task, making it always add the blank line. This simplifies the logic while maintaining the same behavior.

* fix whitespace

Author: liferoad