update main TODO

src/main.cpp

@@ -6,6 +6,7 @@
  * - make an 'overlay' graphic for things like apoapsis, perisapsis, f1, f2,
  *   	flight path
  * - patched conic method for transferring between 2 grav bodies
+ * - test parabolic/hyperbolic trajectories
  * - organize orbit functions into interface/internal functions
  * - add an 'orbits' namespace
  *   - drop orbit from interface functions,