DOC: more improvements in the Environment class

Author: kevin-alcaniz

rocketpy/environment/environment.py

@@ -248,6 +248,8 @@ class Environment:
         Number of ensemble members. Only defined when using Ensembles.
     Environment.ensemble_member : int
         Current selected ensemble member. Only defined when using Ensembles.
+    Environment.earth_rotation_vector : list
+        Earth's angular velocity vector in the Flight Coordinate System.
 
     Notes
     -----