Updated platform schema to support YAML configuration

[terricain]

Description

Fixes configuring the sensor via YAML configuration.

Related Issue

This PR fixes or closes issue: fixes #2

Motivation and Context

Updated the platform schema to make time_offset and time_window optional as they have defaults, as well as added a schema entry for destination

How Has This Been Tested

Tested this by installing my fork with HACS and declaring a YAML sensor.

Home Assistant version: 2023.11.2

Types of changes

• 🐛 Bug fix (non-breaking change which fixes an issue)
• 🚀 New feature (non-breaking change which adds functionality)
• 🌎 Translation (addition or update a translation)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

Whilst this adds a required platform field of destination, I wouldn't call it a breaking change considering it didn't work initially.

Checklist

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