EC2 documentation

[KesterTan]

Description

This PR provides documentation for how to setup Autolab in EC2.

Motivation and Context

How Has This Been 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)

Checklist:

• [ ] I have run rubocop and erblint for style check. If you haven't, run overcommit --install && overcommit --sign to use pre-commit hook for linting
• [ ] My change requires a change to the documentation, which is located at Autolab Docs
• [ ] I have updated the documentation accordingly, included in this PR

Other issues / help required

If unsure, feel free to submit first and we'll help you along.