Use <coderef> for sample files #49
Use <coderef> for sample files #49

Restore highlighting when available for coderefs:
https://github.com/dita-ot/dita-ot/issues/3096

Signed-off-by: Roger Sheen <a61a1add71dadc74037ae5e44ee30713db9a7451@infotexture.net>

infotexture/docs,infotexture/docs,dita-ot/docs