I've spent a good part of this year working on revisions to the RDoc for Array. The revisions include all methods documentation in addition to much of the introductory text (class documentation). Lots more example code.

Check it out:

• 2.7.2: https://ruby-doc.org/core-2.7.2/Array.html
• 2.7.1: https://ruby-doc.org/core-2.7.1/Array.html