[office-comment] ODF 1.2 part 1 cd04 file extensions, odi is useless

In the mimetype list there is also odi mentioned. 
This is a useless option because odg provides everything and more. 
Odg is also more used and easier to know what it means for average users (g for graphics). 

Please add a warning in the list that odg is preferred. 
That odi shouldn't be used, is obsolete/deprecated and remove odi in the next non-backwards compatible version of ODF.