Document usage.

On host01.shore.co.il or different hosts.

README.md

@@ -9,6 +9,20 @@ other Docker containers for jobs. This image registers with the server on
 startup and has the `docker` package already installed (it needs to have the
 dockerd socket mounted inside the container).
 
+## Usage
+
+First of all, get the registration token from
+https://git.shore.co.il/admin/runners. To build and run on `host01.shore.co.il`,
+just run:
+```
+docker-compose build && REGISTRATION_TOKEN='INSERT_TOKEN' docker-compose up -d
+```
+
+If you want to run on a different host (for example `ns4.shore.co.il`), run:
+```
+DOCKER_HOST=ssh://ns4.shore.co.il docker-compose build && DOCKER_HOST=ssh://ns4.shore.co.il REGISTRATION_TOKEN='INSERT_TOKEN' RUNNER_NAME=ns4.shore.co.il docker-compose up -d
+```
+
 ## License
 
 This software is licensed under the MIT license (see `LICENSE.txt`).