Sidebar style and accessibility improvements

[tkajtoch]

Acceptance Criteria

• Sidebar should not have border-right
• Sidebar container (.sidebar-menu) should have the padding set to 2rem 1.5rem
• Sidebar mobile view should open from the left side, not the right side
• Sidebar mobile (open state) width should be configurable via --sidebar-width-mobile (fallback to 300px)
• Sidebar mobile open/close sidebar should be a hamburger icon instead of Open / Close sidebar text
• Sidebar width should be configurable via --sidebar-width (fallback to 300px)
• Filter: Input border, background, color and font properties should be configurable:
  • --sidebar-filter-font-size (fallback to 1rem)
  • --sidebar-filter-font-weight (fallback to 400)
  • --sidebar-filter-color (fallback to #333)
  • --sidebar-filter-background (fallback to transparent)
  • --sidebar-filter-border-color (fallback to #E6E6E6)
  • --sidebar-filter-border-radius (fallback to 0.25rem)
• Path (list item) should have a configurable color and font properties:
  • --sidebar-path-color (fallback to #333)
  • --sidebar-path-font-size (fallback to 0.875rem)
  • --sidebar-path-font-weight (fallback to 400)
• Tag (group) should have a configurable color and font properties:
  • --sidebar-tag-color (fallback to #333)
  • --sidebar-tag-font-size (fallback to 1rem)
  • --sidebar-tag-font-weight (fallback to 600)

[tomaszwylezek]

Looks good to me.