Support glob patterns for directory/file name matching in [filetype] rules

[bendecastro]

Is your feature request related to a problem? Please describe.

Currently, the [filetype] section in theme.toml only supports two special URL patterns:

• url = "*" - matches all files
• url = "*/" - matches all directories

There's no way to style the text color of a specific directory by name. For example, I can customize the icon color for a directory named "Sync" using:

[icon]
append_dirs = [
  { name = "Sync", text = "", fg = "magenta" },
]

But I cannot make the directory name text also appear in magenta. The [filetype] rules don't support glob patterns like **/Sync/ or name-based matching.

Describe the solution you'd like

Support glob patterns or name-based matching in [filetype] rules, similar to how [icon] works. For example:

[filetype]
rules = [
  # Option A: glob pattern support
  { url = "**/Sync/", fg = "magenta" },
  
  # Option B: name-based matching (like icons)
  { name = "Sync", fg = "magenta" },
]

This would allow users to have matching icon and text colors for specific directories/files.

Describe alternatives you've considered

1. Using init.lua to customize rendering - this works but is significantly more complex for what should be a simple theming option
2. Only coloring the icon - this works but creates visual inconsistency between icon and text

Additional context

The [icon] section already supports this functionality with dirs, files, exts, and globs. Extending similar support to [filetype] would provide a consistent and intuitive theming experience.

[Zen-Path]

I spent the last 30 mins trying to fiddle with my config trying to set a custom color for a specific directory, not realizing the feature wasn't implemented yet. Would definitely be useful, since we could have the icon and the text be the same color.

I was trying to set a different color for ".venv" and ".mypy_cache" directories, so it's easier to visually filter them out.