Api cleanup

[calbaker]

• clarifies process for creating SetSpeedTrainSim and SpeedLimitTrainSim
• switches to using RailVehicle directly in place of RailVehicleMap in several places but not exhaustively
• adds new yaml versions of rail vehicle files and tests them:

  altrios/python/altrios/tests/test_rail_vehicles.py

  Lines 4 to 17 in cfcc11e

  	def test_rail_vehicles():
  	"""
  	Verifies that csv- and yaml-defined rail vehicles can be loaded and produce same result
  	"""
  	rail_vehicle_path = alt.resources_root() / "rolling_stock"
  	df = pd.read_csv(rail_vehicle_path / "rail_vehicles.csv")
  	rail_vehicle_map = alt.import_rail_vehicles(str(rail_vehicle_path / "rail_vehicles.csv"))
  	for i, row in df.iterrows():
  	rv_csv = rail_vehicle_map[row['Car Type']]
  	rv_yaml = alt.RailVehicle.from_file(
  	str(rail_vehicle_path / f"{row['Car Type']}.yaml")
  	)
  	assert rv_csv.to_json() == rv_yaml.to_json()

• various other changes to make API for constructing train simulations more clear

[SWRIganderson]

@calbaker
I took a look at the examples in detail this evening. I think we should have more comments in the examples. I'm not saying you should do it though. This is on me too.

I also don't like the commented-out portions of the example that would be making plots. We should either make the plot or delete the code in my opinion.

I do like what you have done with the car yaml files instead of the csv. That seems a lot cleaner.

I have not looked at the rust changes in detail. I'll try to give it look on Thursday.

[calbaker]

@sakhtar312 could you try to get these tests passing?

[sakhtar312]

@calbaker the tests are passing now. Installing the project in developer mode in tests.yaml file (adding -e flag to pip install .) did the trick.

[sakhtar312]

Reviewed the changes and both rust and python tests are passing. Approving the pull request.