Color formatting for brackets in Markdown document calculate incorrectly

[maxengel]

The "Code" app seems to format pairs of brackets from outside-in, which works well for coding. However, when creating a to-do list via Markdown with [ ] where the line contains a link, the first bracket will be black but the second will be grey.

Steps to Reproduce For example with: * [ ] File bug report for [Code](https://github.com/elementary/code/issues/new)

Expected Result The first and second brackets will be the same color, and the third and fourth brackets will be the same color

Actual Behavior The first and fourth brackets have matching colors, and then the second and third brackets have matching colors

Screenshot of Issue