[docs] Heading anchors should appear next to the header

[choldgraf]

In the new theme refresh, the heading anchor characters show up to the far right of the heading, which can be difficult to notice and feels a bit awkward from a UI/UX standpoint:

I'd propose that heading anchors should show up just to the right of heading text when it is hovered, so that it is easier to notice and click.

[tk0miya]

+1