New feature: Optional locations of social icons

[rydmike]

When you add links to socials, they now appear at the bottom of the page. The likelihood of anybody noticing them there, on a long documentation page, is slim to none.

Would it be possible to have configurable location for them?

In a row:

• Top of side menu
• Bottom of side menu
• Left of search bar
• Right of search bar
• Page footer, where there are now

Options should not be exclusive, if you configure multiple locations they appear at each one.

I would personally like to keep the page footer but also in a row at the of the side menu, where they were before.

[rydmike]

Since I got the anchors working again (thx! 😄 #384), I can at least add Twitter as an anchor, so that kind of works too for where I want to put a link to it.