Fix font embedding

This PR adds embedded webfonts for titles and bodytext, providing a more unified appearance across different platforms. It uses Miso Regular for body, and League Gothic for titles (replacing the previous choice of Impact).

Also updates the logo for Winterwell Associates.

N.B. The embedded fonts are licensed for unlimited use from fontspring.com. Probably not a problem, but worth noting in case in adversely affects any licence you might want to throw onto this codebase.