Use tech-docs repository for technical documentation

[lmcglohon]

Description

Updated documentation scripts to use the tech-docs repo to build jekyll site

Motivation and Context

This should make it easier for folks to manage the technical documentation for ArchivesSpace moving forward.

How Has This Been Tested?

Visually looked at Jekyll site locally

Screenshots (if appropriate):

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)

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 read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.