add navigation rendering

• change YAML structure
• upgrade navigation library version
• add URL resolver
• navigation TWIG extension

readme cleanup

v0.4.1

remove unnecessary installation step from README

add more voters; move code to library

• move factory and navigation items to library
• add more voters
• clean up the code base
• update navigation library

Items factory

• add factory
• add prefix matcher

upgrade navigation library

v0.2.0

upgrade navigation library; move voters

YAML Navigation provider

• initial setup
• navigation provider which loads navigation from YAML