Master

See merge request !7

# Conflicts:
#   README.md

redo menus

See merge request !6

more extensible trait, custom err, interp attrs

See merge request !5

tree draw, interaction input, change interactable trait

See merge request !4

interactable trait, Tree outline, interaction loop

See merge request !3

add input loop, draw function

See merge request !2

initial. set up structure and plotters lib

See merge request !1