upgrade packages, add collapsible side nav

[kahboom]

and a bunch of other changes..

demo here

• update all packages, including to font awesome 5 (required some class + config changes)
• add collapsible side nav
• extract theme-specific options into site-specific options (e.g. menu is now defined in config/menus.toml instead of themes/syndesis/theme.toml)
• add syndesis ascii artwork for dev environment, display port number, change port number from default
• change font to Quicksand

cc @zregvart @Delawen