generic Renderer for render targets richer than String

[rpm0372]

Changed org.commonmark.node.Node.Renderer to Renderer<T> and updated all three type descendants to concretize as Render<String>.

This change was motivated by my project's need to render markdown to targets not easily represented as a single String.

[robinst]

This change was motivated by my project's need to render markdown to targets not easily represented as a single String.

Can you explain this more? So you want to be able to have a Renderer<Something>? Why can't you define your own interface (and delegate to commonmark's Renderer)?

[rpm0372]

Because commonmark's Renderer interface only supports returning a String.