Refined function list

Author: Jim Carr

README.md

@@ -48,7 +48,14 @@ If you're interested in this topic, please buy the book! It provides far more de
 - [x] Calculate -> Approximate position of planet
 - [x] Calculate -> Precise position of planet
 - [x] Calculate -> Visual aspects of planet (distance, angular diameter, phase, light time, position angle of bright limb, and apparent magnitude)
-- [ ] Calculate -> Position of comet (elliptical and parabolic)
+
+### Comets
+
+- [ ] Calculate -> Position of comet (elliptical)
+- [ ] Calculate -> Position of comet (parabolic)
+
+### Binary Stars
+
 - [ ] Calculate -> Binary star orbit data
 
 ### The Moon