Fix: Better top header layout on iPhone

fix the right Nav goes down issue
Docs: Update docs
Fix: change back to slimScroll to fix left menu can not scroll on mobile bug
Chore: Remove niceScroll and perfectScrollbar
Chore: update i18n
Feat: Init Add LESS CSS
Feat(Sass2Less): Update Bootstrap and variables
Feat(Sass2Less): successfully import all files