Minor adjustments to typography

This cuts down slightly on some text sizes, which should help
readability on some devices due to better pixel size, esp. on mobile
devices.  It also uses the same font for the "top level" headers as the
menu for consistency.
Updated logo typography specifications
Merge pull request #338 from ReedCopsey/fonts

Minor adjustments to typography
Update index.md
Update index.md
Update index.md
content and typography cleanup
content and typography cleanup (2)
content and typography cleanup
content and typography cleanup
content and typography cleanup
web content cleanup
typography cleanup
web content cleanup
content and typography cleanup
content cleanup
Update index.md

Correct link to FSharp.CloudAgent
content cleanup
content cleanup
content cleanup