flutter_package / gpt_markdown

fix: support balanced parentheses in image and link URLs

Fixed a parsing issue where URLs containing parentheses would be incorrectly truncated, breaking image and link rendering.
Implements a balanced parentheses parser compliant with CommonMark
Supports nested parentheses like (value(nested))
Maintains backward compatibility
Efficient O(n) algorithm with clean logic
Verified with unit, integration, regression, and edge case tests

…functionality for better list rendering.

…edListBuilder` and `unOrderedListBuilder` parameters for enhanced list rendering in GptMarkdown.

Thanks for the contribution.

Add imageBuilder to example
Fix file name typo

+ highlightBuilder && - default padding on code block