The "/leaves" page:
Show leaf check-ins in a timeline.  By default only open leaves
are listed.
A "leaf" is a check-in with no children in the same branch. A "closed leaf" is a leaf that has a "closed" tag. An "open leaf" is a leaf without a "closed" tag.
Query parameters:
- all
 - Show all leaves
 - closed
 - Show only closed leaves
 - ng
 - No graph
 - nohidden
 - Hide check-ins with "hidden" tag
 - onlyhidden
 - Show only check-ins with "hidden" tag
 - brbg
 - Background color by branch name
 - ubg
 - Background color by user name