datalab issue guide should better describe the relevant cleanlab columns

[jwmueller]

For instance, near duplicate issue has relevant columns:
near_duplicate_score, near_duplicate_sets

but neither of these is explained anywhere in Near Duplicates section of the issue type guide.
These are both important concepts to understand and should explained there.

Same for the other issue types. You can follow our explanations at:
https://help.cleanlab.ai/guide/concepts/cleanlab_columns/#near-duplicates

and use that for inspiration when implementing this.