Add XDITA section and more about MDITA and HDITA (#230)
Add XDITA section and more about MDITA and HDITA (#230)

Signed-off-by: markgif <448c664a90cdb07a3b96bc0e744b5c37c0e49849@earthlink.net>
infotexture/docs,infotexture/docs,dita-ot/docs