Cobalt Spark v0.2 — Live Git updates

What's changed since v0.1

• Live Git updates — the Git segment can now refresh while the prompt is idle using fswatch.
• Expanded Git status — ahead/behind tracking, commits unique to branches without an upstream, and early detection of prefetched remote changes.
• Smarter branch display — configurable shortening of common branch prefixes keeps long branch names compact.
• Zsh plugin manager support — Cobalt Spark can now be installed with Zinit, Antigen, zplug, and other compatible managers.
• Added a ZLE widget for quickly copying the current working directory.

Plus numerous fixes, performance improvements, and documentation updates.

Full Changelog: v0.1...v0.2