Feature Request: Additional Font Weight Classes

Created by: planetoftheweb

I think it would be great to include some more font-weight options in bootstrap. Even when you look at the documentation, you can see that the weights have been modified because current design sensibilities call for a wider range of font weights that the default. I realized that when I'm creating bootstrap projects, I end up modifying the font-weights a lot, so maybe this could be added into the classes.

Although font-weight-bold and font-weight-normal exist, I feel like there needs to be a bit more broad. I'm proposing adding some font-weight classes.

font-weight-light font-weight-medium font-weight-normal font-weight-bold font-weight-heavy

These could be tied to sass variables. We could also add numbered font-weight classes.

font-weight-100 font-weight-300 ...etc