- FEATURE
  - add `geekdocHidden` param to exclude pages/sections from rendered file-tree menu
  - add `geekdocFlatSection` param to include only section link into rendered file-tree menu
  - add `geekdocBreadcrumb` param to control breadcrumb naviation
  - add `geekdocNextPrev` param to page navigation links
- BUGFIX
  - normalize variable and parameter names
  - fix `geekdocLogo` param and custom logo handling