How do I add existing comments to RDoc in Ruby?

Question: I want to format my existing comments as 'RDoc comments' so they can be viewed using ri.

What are some recommended resources for starting out using RDoc?

Solution: A few things that have bitten me:

• :main: -- RDoc uses only the last one evaluated; best to make sure there's only one in your project and you don't also use the --main command-line argument.
• same as previous, but for :title:
• :section: doesn't work very well