- added part for fixed navbar/footer incl. the responsive classes
- added anchor info for fixed navbar
- added .dropdown-menu-lg/-xl info in main-header docs
- added custom plugin colors in layout colors part
  - custom-range
  - custom-switch
  - bootstrap slider
  - icheck-bootstrap

- updated assets
- added bootstrap-duallistbox in dependencies
- updated colors section in layout
- finished components/cards
- created & finished components/boxes
- added missing position relative to .info-box

- updated docs assets
- added yarn install info
- overhauled color parts in layout.md
- added components/main-sidebar, /control-sidebar & /cards
- updated title in components/main-header
- created blank pages javascript/control-sidebar& /push-menu to ensure docs generation
- renamed Sidebar to Main Sidebar

- jekyllrb preset for gh-pages with AdminLTE 3 layout
- rebuild menu structure like AdminLTE v2.4 docs
- modified npm/Plugins.js to update docs assets with every production run