Update instructions.md

[chris-calhoun]

Description

Updated instructions to include proper sectors and systems relationship

Related Issue

none

Motivation and Context

The previous version of this project did not have the ability to add systems to a sector.

How Can This Be Tested?

none

Screenshots (if appropriate):

Types of changes

• [x] 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)