Add text-regression tasks

[adrinjalali]

Similar to #100, but we should also make sure the config file and the README contain the right components for the widget to work.

This might also involve adding a text-classification alias on the api-inference-community side.

[BenjaminBossan]

Once those are done, we should an entry for sklearn here.

[adrinjalali]

That list seems quite misleading, as in, it doesn't seem to show what tasks are supported by each library, so we could already add ours there. But I'm in no rush.

[BenjaminBossan]

Yeah, no rush, but it seems that with those tasks finished, we have covered the most important ones for sklearn.

[adrinjalali]

Renamed since we now support text-classification.