Update plugin.yml

[clickednebula3]

Description

changed plugin.yml for example-plugin description to make it clearer

Motivation and Context

specifies that the example plugin is just a use-case for the AnnoyingAPI, rather than an example of what is considered the AnnoyingAPI

How Has This Been Tested?

This is not tested.

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 change)
• Clarity enhancement

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have read the CONTRIBUTING document.
• All new and existing tests passed.