Feature: Automatically add ID to headings

[mohits]

Hi, I am working on this: jgarber/redcloth#85 since a Jekyll theme I am using can automatically create a table of contents but requires that each heading have an ID that it can refer to. I am looking at adding support to RedCloth and it will need a small change to the allowed attributes configuration.

Would there be interest in this? If yes, I will prepare PRs for both repositories (RedCloth and jekyll-textile-converter) so that it's available for everyone.

Thanks!