Make "val" fields public

[kettei-sproutty]

Is your feature request related to a problem? Please describe.

Hi!
I've noticed that some val properties inside structs such as Color, VertAlign etc, are not marked as public in the codebase. I wanted to know whether this is intentional and if there are plans to keep them as private, or if it's possible to consider marking them as public.

Describe the solution you'd like

I would like to being able to read properties such as val and some run_properties values when i'm reading a docx file.

Describe alternatives you've considered

None

Additional context

None