Update README with installation, usage, and development instructions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dd32

README.md

@@ -1,2 +1,42 @@
 # wpcli-cron-concurrent
-Runs WordPress cron tasks concurrently via wp-cli.
+
+A WP-CLI package that runs WordPress cron tasks concurrently instead of sequentially.
+
+By default, `wp cron event run --all` processes each task one at a time. This package spawns parallel subprocesses so multiple cron hooks execute simultaneously, with a live progress display showing each task's status and output.
+
+## Installation
+
+```bash
+wp package install dd32/wpcli-cron-concurrent
+```
+
+## Usage
+
+```bash
+# Run all pending cron tasks concurrently (default: 5 at a time)
+wp cron-concurrent run
+
+# Run only hooks matching a substring
+wp cron-concurrent run --filter=woocommerce
+
+# Limit to 3 concurrent tasks
+wp cron-concurrent run --concurrent=3
+```
+
+## Options
+
+| Option | Description | Default |
+|---|---|---|
+| `--filter=<string>` | Only run hooks whose name contains this string | _(all hooks)_ |
+| `--concurrent=<n>` | Maximum number of tasks to run at the same time | 5 |
+
+## Development
+
+Requires Node.js (for wp-env) and Docker.
+
+```bash
+npm install
+npm run env:start
+npm test
+npm run env:stop
+```