Add --ignore flag to CLI to support excluding paths from file watching

[cleverbunnykeith]

The Tailwind CSS CLI currently supports --watch, which works well for most workflows. However, it lacks a mechanism to ignore specific paths or globs from triggering rebuilds.

This feature would add a new --ignore (-g) flag that passes ignore patterns directly to the underlying @parcel/watcher instance.

Motivation

I'm working with Tailwind in an Elixir-based build system that watches the entire project directory, including template files and generated assets. Without the ability to ignore directories, such as priv/static/assets, any change in built output triggers an unnecessary rebuild — creating a feedback loop of changes.

This --ignore flag would solve that problem cleanly and enables a broader range of integrations, particularly in environments where full-project watching is required.

Example usage

tailwindcss -i input.css -o output.css --watch --ignore "priv/static/assets/**"

Let me know if there are any edge cases you'd like to see covered or if you'd prefer a different flag signature.

Ref: phoenixframework/tailwind#128