doc: Write an EXAMPLES section for the tree(3) manpage(s)
completed by: yeputons
mentors: Samuel J. Greear, Pratyush Kshirsagar
tree(3) defines a set of macro's implementing splay and red-black tree's.
Write an EXAMPLES section for the tree(3) manpage(s) showing the usage of the functions defined in those manpage(s) in a plausible, real-world and if possible only semi-contrived scenario.
All examples should follow the style guidelines in the style(9) manpage.
All examples should be written in a manner that is self-documenting and make copious use of comments in order to explain the actions being taken.
Examples should be real and working code. They should not include headers or even a main function, but it should be reasonable for a developer to copy and paste an example from a manpage and expect it to work.
An example of a manpage with excellent example code is umtx(2).
Deliverables: A complete EXAMPLES manpage section in mdoc format.