[Docs] Document DolphinScheduler integration with Docker Compose deployments

## Background

The FAQ mentions that users can use scheduling tools such as Apache DolphinScheduler to manage SeaTunnel jobs. Users who deploy SeaTunnel through Docker Compose still need practical guidance for integration details, especially the meaning of `SEATUNNEL_HOME` when the scheduler runs outside or inside a container.

A common question is: when SeaTunnel is deployed with Docker Compose, what SeaTunnel home path should be configured in DolphinScheduler?

## Goal

Document how to configure DolphinScheduler to submit SeaTunnel jobs when SeaTunnel is deployed with Docker Compose or containerized paths.

## Documentation location

This content should be placed under the practical tools / ecosystem section, not under connector docs.

Suggested files:

- `docs/en/tools/overview.md` or a new page under `docs/en/tools/`
- `docs/zh/tools/overview.md` or a new page under `docs/zh/tools/`

If a new page is added, please also wire it into the relevant sidebar.

## Suggested scope

The update should explain:

1. What `SEATUNNEL_HOME` means for a scheduler integration.
2. The difference between host paths and container paths.
3. How to decide the correct path when DolphinScheduler runs on the host.
4. How to decide the correct path when DolphinScheduler also runs in Docker or Kubernetes.
5. A minimal example using the common SeaTunnel container path, such as `/opt/seatunnel`, if that is accurate for the current Docker image.
6. Any required volume mounts or network assumptions.

## Acceptance criteria

- The docs give a direct answer for Docker Compose deployments.
- The docs clearly distinguish host-side and container-side paths.
- The content is added under the practical tools / ecosystem docs section.
- English and Chinese docs are consistent.
- The example is checked against the current SeaTunnel Docker image or Docker Compose deployment docs.