Line numbers and permalinks for code blocks

Outline already has good support for permalinks to document headers. This would be extending that functionality to specific lines within a code block as with a gist. For example:



Key features:
• code blocks should have line numbers
• a user should be able to select one or more lines in a code block that results in a hash fragment being appended to the end of the url. There should be some sort of highlighting associated with the selection.
• Someone clicking on a permalink (with the appropriate permissions) should be able to view the document with the appropriate lines highlighted.