The AsciiDoc editor is available from version 2.5.295 and up.
AsciiDoc is a lightweight and semantic markup language primarily designed for writing technical documentation. The language can be used to produce a variety of presentation-rich output formats, all from content encoded in a concise, human-readable, plain text format.
See the AsciiDoc Language Documentation for more information.
Note that only a limited set of AsciiDoc features are supported at the moment.