Update README.md

README.md

@@ -3,11 +3,13 @@ GitHub Markup
 
 This library is the first step of a journey that every markup file in a repository goes on before it is rendered on GitHub.com:
 
-0. This library converts the raw markup to HTML. See the list of [supported markup formats](#markups) below.
-0. The HTML is sanitized, aggressively removing things that could harm you and your kin—such as `script` tags, inline-styles, and `class` or `id` attributes. See the [sanitization filter](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/sanitization_filter.rb) for the full whitelist.
-0. Syntax highlighting is performed on code blocks. See [github/linguist](https://github.com/github/linguist#syntax-highlighting) for more information about syntax highlighting.
-0. The HTML is passed through other filters in the [html-pipeline](https://github.com/jch/html-pipeline) that add special sauce, such as [emoji](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/emoji_filter.rb), [task lists](https://github.com/github/task_list/blob/master/lib/task_list/filter.rb), [named anchors](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/toc_filter.rb), [CDN caching for images](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/camo_filter.rb), and  [autolinking](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/autolink_filter.rb).
-0. The resulting HTML is rendered on GitHub.com.
+1. This library converts the raw markup to HTML. See the list of [supported markup formats](#markups) below.
+1. The HTML is sanitized, aggressively removing things that could harm you and your kin—such as `script` tags, inline-styles, and `class` or `id` attributes. See the [sanitization filter](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/sanitization_filter.rb) for the full whitelist.
+1. Syntax highlighting is performed on code blocks. See [github/linguist](https://github.com/github/linguist#syntax-highlighting) for more information about syntax highlighting.
+1. The HTML is passed through other filters in the [html-pipeline](https://github.com/jch/html-pipeline) that add special sauce, such as [emoji](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/emoji_filter.rb), [task lists](https://github.com/github/task_list/blob/master/lib/task_list/filter.rb), [named anchors](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/toc_filter.rb), [CDN caching for images](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/camo_filter.rb), and  [autolinking](https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/autolink_filter.rb).
+1. The resulting HTML is rendered on GitHub.com.
+
+Please note that **only the first step** is covered by this gem — the rest happens on GitHub.com.  In particular, `markup` itself does no sanitization of the resulting HTML, as it expects that to be covered by whatever pipeline is consuming the HTML.
 
 Please see our [contributing guidelines](CONTRIBUTING.md) before reporting an issue.
 
@@ -17,7 +19,7 @@ Markups
 The following markups are supported.  The dependencies listed are required if
 you wish to run the library. You can also run `script/bootstrap` to fetch them all.
 
-* [.markdown, .mdown, .mkdn, .md](http://daringfireball.net/projects/markdown/) -- `gem install redcarpet` (https://github.com/vmg/redcarpet)
+* [.markdown, .mdown, .mkdn, .md](http://daringfireball.net/projects/markdown/) -- `gem install commonmarker` (https://github.com/gjtorikian/commonmarker)
 * [.textile](http://www.textism.com/tools/textile/) -- `gem install RedCloth`
 * [.rdoc](https://rdoc.github.io/rdoc/) -- `gem install rdoc -v 3.6.1`
 * [.org](http://orgmode.org/) -- `gem install org-ruby`
@@ -67,4 +69,4 @@ GitHub::Markup.render_s(GitHub::Markups::MARKUP_MARKDOWN, '* One\n* Two')
 Contributing
 ------------
 
-See [Contributing](CONTRIBUTING.md)
+See [Contributing](CONTRIBUTING.md).