Update some configuration options to match prod

[ericholscher]

Mainly:

• Remove RTD specific path logic that isn't needed
• Set proper SITEURL

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:books: Documentation preview :books:: https://read-the-docs-website--205.com.readthedocs.build/

[ericholscher]

@agjohnson I don't think we're actually using the publishconf anywhere, probably need to update the RTD command that is running.