Add a document page for all available metrics

[2010YOUY01]

Is your feature request related to a problem or challenge?

Original discussion question: #16572

There are many fine grained metrics in DataFusion, and many of them's meaning are not obvious. In order to find out its meaning, now we have to search for its name in the codebase, then follow several indirections, and finally get the comment. This process is not easy.

Describe the solution you'd like

Add a document page for all available metrics:

• It can be organized by operators
• Would be great if it can be auto-generated from code

Describe alternatives you've considered

No response

Additional context

No response

[alamb]

There is https://datafusion.apache.org/user-guide/explain-usage.html which is related, though does not document the metrics

I agree it would be great to automatically generate this from the code somehow

Thank you for filing this