feat(core, Сolor): added support for custom escape characters
The esc() method now checks state.escapeCharacters, if defined, and includes its characters in the escape regex.
This allows context-specific escaping — for example, in the color mark, to escape parentheses in user input without interfering with the markup syntax.
Preview is ready.
Visual Tests Report is ready.
https://github.com/nkjmsss/markdown-it-color/pull/17
Found one issue — in markup mode, using the toolbar button doesn’t add escaping. Since we work with plain text there, I’m not sure how easy it is to support
https://github.com/user-attachments/assets/b8102fd1-93cd-473e-a7aa-17f3935acf42