Fixes line-height for h1 in readme, instead of overflow 'hack'.

> Removes scrolling due to to small line-height. This is an alternative solution
to #350 and #352, as adding overflow hidden doesn't solve the problem, but
potentially cuts the lower part of the font.

I added this PR as I feel `overflow-y: hidden` ( #352 ) is not the correct solution to the problems described in #350 and #378. Adding `overflow-y: hidden` will potentially just cut the lower part of the font. The real issue here is the line-height. The line height is too small in contrast to the font-size. You could also potentially remove the line-height, but as the font is loaded lazily, you would get a "temporary moment of ugliness" and a site jump when the font is loaded.