Add Recommendations component

[tterb]

Description

Added a component for Disqus Recommendations and modified the example site to support Recommendations.
For Recommendations to actually be collected and displayed on the example site, the website needs to be published publicly somewhere, which I'm still working on.

Motivation and Context

Required for using the new Standalone Recommendations.

How Has This Been Tested?

Tested on the example site and with additional unit tests.

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.
• All new and existing tests passed.

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This change is