Styling, spacing, sizing

[andrew-vandenberg]

This is purely cosmetic, but we may want to spend more time with the header sizes, header spacing, and so forth as we send this out to more people. For example, the links on the recipes page jump out as being large compared to the styling of other pages. Again, not critical, but just something to think about

[datasciencecookbook]

fully support. I don't think we were rigorous about keeping the use of headers consistent across pages. More CSS styling could be nice too