update worker docs to include periodic script features (#1042)

* update

* Update index.mdx

---------

Co-authored-by: Ruben Fiszel <[email protected]>

Author: dieriba

docs/core_concepts/9_worker_groups/index.mdx

@@ -46,7 +46,8 @@ Examples of configurations include:
 
 1. [Assign different jobs to specific worker groups](#set-tags-to-assign-specific-queues) by giving them tags.
 2. [Set an init script](#init-scripts) that will run at the start of the workers (e.g. to pre-install binaries).
-3. [Dedicate your worker to a specific script or flow](#dedicated-workers--high-throughput) for high throughput.
+3. [Set a worker script](#worker-scripts) that will run at regular intervals on workers (e.g. for maintenance tasks).
+4. [Dedicate your worker to a specific script or flow](#dedicated-workers--high-throughput) for high throughput.
 
 ## Assign custom worker groups
 
@@ -274,7 +275,8 @@ Examples of configurations include:
 
 1. [Assign different jobs to specific worker groups](#set-tags-to-assign-specific-queues) by giving them tags.
 2. [Set an init script](#init-scripts) that will run at the start of the workers (e.g. to pre-install binaries).
-3. [Dedicate your worker to a specific script or flow](#dedicated-workers--high-throughput) for high throughput.
+3. [Set a worker script](#worker-scripts) that will run at regular intervals on workers (e.g. for maintenance tasks).
+4. [Dedicate your worker to a specific script or flow](#dedicated-workers--high-throughput) for high throughput.
 
 ## Alerts
 
@@ -363,6 +365,32 @@ Under the [Cloud plans & Self-Hosted Enterprise Edition](/pricing), they can be
 	/>
 </div>
 
+## Worker scripts
+
+Worker scripts are bash scripts that run at regular intervals on workers, complementing init scripts which only run at worker startup. While init scripts handle one-time setup tasks like installing dependencies or configuring the environment, worker scripts are designed for ongoing maintenance tasks that need to be executed repeatedly during the worker's lifetime.
+
+### Key differences from init scripts
+
+- **Init scripts**: Run once when the worker starts, ideal for setup and configuration tasks
+- **Worker scripts**: Run continuously at specified intervals (minimum 60 seconds), ideal for maintenance and monitoring tasks
+
+### Common use cases
+
+Worker scripts are particularly useful for:
+
+- **System maintenance**: Cleaning temporary files, rotating logs, or performing health checks
+- **Cache management**: Clearing expired cache entries or warming up caches  
+- **Resource monitoring**: Collecting metrics or monitoring system resources
+- **Security tasks**: Running periodic security scans or updating security configurations
+
+### Configuration and execution
+
+Under the [Cloud plans & Self-Hosted Enterprise Edition](/pricing), worker scripts can be configured from the Windmill UI in the worker group settings, similar to init scripts.
+
+When adjustments are made in the Worker Management UI, the workers will shut down and are expected to be restarted by their supervisor (Docker or k8s).
+
+The execution of worker scripts is inspectable in the superadmin workspace, with Kind = All filter. The path of those executions are `periodic_script_{worker_name}_{timestamp}`.
+
 ## Dedicated workers / High throughput
 
 Dedicated Workers are workers that are dedicated to a particular script. They are able to execute any job that target this script much faster than normal workers at the expense of being capable to only execute that one script.