FIX - add alignment info to imgproc and figure shortcodes

[aormsby]

The imgproc and figure shortcodes have some alignment issues. The <img> element is always left-aligned within the figure element and can look strange when the caption is wider than the image. (Maybe related to recent figure styling updates?)

My current fix is to add the class position parameters to the internal img tags. The alignment of the image will match the alignment of the figure. I'm wondering if it's a little hacky, but it does work.

If this works for you, it should be ready to go.

[aormsby]

In addition, I've added alt text and hyperlinks to my image options over here. I'm happy to include those enhancements in my PR if you're interested in having them. Just let me know. :)

[panr]

Sorry for a late response (I don't where I've been for the whole year...). I'd be nice if you still want to add alt and hiperlinks :)