table of contents with lengthy ordered lists has very tight left padding

[thescientist13]

If you go to a page with a length list of items in the right side Table of Contents component like the Plugin API docs page which has nine items on it, by the time the content gets to the bottom of the ToC container, the padding on the left starts to get super tight, almost getting cut off

Would be good to make sure that this text always has a little room to breath on the left.

[darragh4]

I submitted a pull request; I've centred the text to remove the tightness on the left-hand side.