Minor relocation and read me update

Author: jbrodovsky

core/README.md

@@ -38,3 +38,7 @@ In addition to the core library there is a basic command line tool for evaluatin
 
 1. **Open Loop**: This mode processes a set of inertial measurements (IMU data) and outputs the estimated position, velocity, and orientation over time in an open loop INS configuration; i.e. dead reckoning. This can be used to build an error state filter on top of or to develop a drift trajectory to compare your INS implementation to.
 2. **Closed Loop**: This mode processes a set of inertial measurements (IMU data) and outputs the estimated position, velocity, and orientation over time in a closed loop INS configuration; i.e. with aiding from an external source such as GNSS or a visual odometry system. This specific implementation uses a three-state position measurement (latitude, longitude, and altitude) to correct the INS state. This can be used to compare alternative or complimentary navigation aides to GPS-aided performance.
+
+## Installation
+
+There is both a library of navigation functionality and a command line tool for running dead-reckoning and cannonical closed-loop INS simulations. The library can be added to your Rust project as a dependency in your `Cargo.toml` file: `cargo add strapdown-rs`. The command line tool can be installed via `cargo install strapdown-rs`.

core/src/main.rs

@@ -21,7 +21,7 @@ struct Args {
     output: PathBuf,
 }
 
-fn write_results_to_csv(
+fn write_results_to_csv( // TODO: make this public and move to sim.rs
     results: &[NavigationResult],
     output: &PathBuf,
 ) -> Result<(), Box<dyn Error>> {

core/src/sim.rs

@@ -195,7 +195,6 @@ pub struct NavigationResult {
     )]
     pub covariance: Option<Vec<f64>>,
 }
-
 impl NavigationResult {
     /// Creates a new NavigationResult with default values.
     pub fn new(
@@ -346,7 +345,6 @@ impl NavigationResult {
         Ok(records)
     }
 }
-
 /// Custom serializer for the covariance field to serialize it as a single string in CSV
 fn serialize_covariance<S>(cov: &Option<Vec<f64>>, serializer: S) -> Result<S::Ok, S::Error>
 where
@@ -365,7 +363,6 @@ where
         None => serializer.serialize_none(),
     }
 }
-
 /// Custom deserializer for the covariance field to deserialize from a string in CSV
 fn deserialize_covariance<'de, D>(deserializer: D) -> Result<Option<Vec<f64>>, D::Error>
 where
@@ -385,7 +382,6 @@ where
         _ => Ok(None),
     }
 }
-
 /// Run dead reckoning or "open-loop" simulation using test data.
 ///
 /// This function processes a sequence of sensor records through a StrapdownState, using