Add instructions on how to split the document.write method and download dependencies and use locally

[JMHeartley]

Description

Motivation and Context

closes #190

How Has This Been Tested?

Screenshots (if appropriate)

Types of changes

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

Checklist

• [x] My code follows the code style of this project.

[coliff]

thank you 👍