`@since` annotation styling

[pascalduez]

Moved from SassDoc/sassdoc#416

The current styling on the @SInCE annotation is quite strange.
It's put on the right side, above the actual element, which sometimes makes it look like it belongs to something else.

Example:

Here the "since 1.0.2" is actually part of the variable $colors, but it looks like it belongs to "Variables".

Can we please add it inline with the variable/function name?

E.g. "Colors - since v1.0.2"

[KittyGiraudel]

Nice catch. I'll try to fix it.

[Tarabass]

I was planning on creating an issue for this as well. I think I fixed it, so I will try to create a pullrequest..

Edit:
Created a pull request. I'm not very familiar with pull request, so please be gentle if something is going wrong..

#81