ld-monitor: Fix conifg examples and add to plugin file

[BrianJKoopman]

Description

This makes the naming convention between the instance-id and docker compose service name consistent, which host mangers need. It also adds the explicit port mapping, which the agent needs as data gets sent to it from another device, rather than it reaching out to the device (which would require the 'host' network mode.)

We also add the agent to the plugin file so it can be launched by ocs-agent-cli.

Motivation and Context

Noticed these while deploying the agent on site.

How Has This Been Tested?

Largely tested on site. The plugin part hasn't been tested yet.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.