use types to streamline kmer parsing

README.md

@@ -2,16 +2,16 @@
 
 `krust` is a [k-mer](https://en.wikipedia.org/wiki/K-mer) counter--a bioinformatics 101 tool for counting the frequency of substrings of length `k` within strings of DNA data. It's written in Rust and run from the command line. It takes a fasta file of DNA sequences and will output all canonical k-mers (the double helix means each k-mer has a [reverse complement](https://en.wikipedia.org/wiki/Complementarity_(molecular_biology)#DNA_and_RNA_base_pair_complementarity)) and their frequency across all records in the given fasta file.
 
-Run `krust` on the test data* in the [`krust` Github repo](https://github.com/suchapalaver/krust), searching for kmers of length 5, like this:
+Run `krust` to count *5*-mers like this:
 
 ```bash
-cargo run --release 5 your/local/path/to/cerevisae.pan.fa > output.tsv
+cargo run --release 5 your/local/path/to/fasta_data.fa > output.tsv
 ```
 
-or, searching for kmers of length 21:  
+or, searching for *21*-mers:  
 
 ```bash
-cargo run --release 21 your/local/path/to/cerevisae.pan.fa > output.tsv
+cargo run --release 21 your/local/path/to/fasta_data.fa > output.tsv
 ```
 
 `krust` prints to `stdout`, writing, on alternate lines:
@@ -24,6 +24,4 @@ cargo run --release 21 your/local/path/to/cerevisae.pan.fa > output.tsv
 ...
 ```  
 
-`krust` uses the [`rust-bio`](https://docs.rs/bio/0.38.0/bio/), [`rayon`](https://docs.rs/rayon/1.5.1/rayon/), and [`dashmap`](https://docs.rs/crate/dashmap/4.0.2) Rust libraries.  
-
-*Unusual, yes, to provide this data in the repo, but it's helped me spread word about what I'm doing.
+`krust` uses [`rust-bio`](https://docs.rs/bio/0.38.0/bio/), [`rayon`](https://docs.rs/rayon/1.5.1/rayon/), and [`dashmap`](https://docs.rs/crate/dashmap/4.0.2).  

src/configuration.rs → src/config.rs

@@ -1,6 +1,6 @@
 use std::{env, error::Error, path::PathBuf};
 
-/// Parsing command line k-size and filepath arguments.
+/// Parsing command line k-size and filepath arguments
 pub struct Config {
     pub k: usize,
     pub path: PathBuf,