update main TODO

src/main.cpp

@@ -1,6 +1,10 @@
 
 /*
  * TODO:
+ * - organize orbit functions into interface/internal functions
+ * - add an 'orbits' namespace
+ *   - drop orbit from interface functions,
+ *   	eg) 'orbitGetTimeOfFlight()' becomes 'getTimeOfFlight()'
  * - make an 'overlay' graphic for things like apoapsis, perisapsis, f1, f2,
  *   	flight path
  * - impulsive orbital maneuvers