Let dropdown menus function as the heading of the instructions

[vbrown608]

trafficstars

I suggest that we remove instruction headers like "Plesk on Debian 8 (jessie)" and instead use the the dropdown menus.

Then we can keep them in view on scroll so users can easily switch between instructions.

[SwartzCr]

My 2 cents are that people might not notice that the URL is updating and getting rid of the perma-link-link will confuse some users

[mfb]

We could keep the dropdowns in view without getting rid of the header.

Also, a quick scroll to the top of the dropdowns would be slicker than having the browser jump to the anchor link.