move files into src, add make clean, update for Elm 0.13
parser compiles
revert for 0.12.3 because 0.13 isn't really usable yet and we don't need anything from it. parser seems to work, add edit.html to test it live
renders basic problems!
render triangles
fix some triangle trig. add parallelogram rendering, quadrilateral rendering (still not sure about)
blank problem for index.html