Add FontAwesome assets (#1734)

Fixes #1472. TTF fonts were included as part of the FontAwesome kit, but
I opted to not add them because basically every browser won't use them
and it just pollutes the repo.

docs/.styleguide

@@ -12,5 +12,6 @@ modifiableFileExclude {
   \.ico$
   \.rknn$
   \.svg$
+  \.woff2$
   gradlew
 }