add superscript and subscript to RunProperties

[alexkowalenko]

Description

Add the ability to change the text formatting to superscript and subscript.

Expected Behavior

The text will have super and subscripts.

Actual Behavior

There seems to be no way to do this. Can't find a function call on RunProperties that supports this. I imagine that it would like something like SetBold(bool).

[tbaliance]

Once this is merged in, you can do something like:

run.Properties().SetVerticalAlignment(sharedTypes.ST_VerticalAlignRunSuperscript)

[alexkowalenko]

Thanks!