Update for PMLB1.0 release

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Thank you for this neat package! I'm not sure if you already know this, but we're preparing for a PMLB1.0 release. There are some breaking changes regarding dataset urls, and I would love to make a PR to ensure pmlblite compatible with the updates.

Also, do you plan to submit this package to CRAN? I'm happy to help with that as well. We're planning to write a manuscript for this new PMLB release and would love to include pmlblite. Please let me know if you would like to contribute!

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Hi there -- just pinging to see if you're accepting PR at the moment! @makeyourownmaker
PMLB v1.0 was released over the weekend!