add readme

Signed-off-by: Guillaume W. Bres <guillaume.bressaix@gmail.com>

cggtts/README.md

@@ -0,0 +1,38 @@
+CGGTTS 
+======
+
+Rust library to parse and generate CGGTTS data.
+
+[![crates.io](https://img.shields.io/crates/v/cggtts.svg)](https://crates.io/crates/cggtts)
+[![Rust](https://github.com/gwbres/cggtts/actions/workflows/rust.yml/badge.svg)](https://github.com/gwbres/cggtts/actions/workflows/rust.yml)
+[![crates.io](https://docs.rs/cggtts/badge.svg)](https://docs.rs/cggtts/badge.svg)
+[![crates.io](https://img.shields.io/crates/d/cggtts.svg)](https://crates.io/crates/cggtts)    
+
+CGGTTS is a file format to describe a local clock behavior against a single or the combination of clocks embedded in Satellite Vehicles (SV).  
+Exchanging CGGTTS files enables so called "Common View" Time Transfer.
+
+CGGTTS is specified by the Bureau International des Poids & des Mesures (BIPM):
+[CGGTTS 2E specifications](https://www.bipm.org/documents/20126/52718503/G1-2015.pdf/f49995a3-970b-a6a5-9124-cc0568f85450)
+
+This library only supports revision **2E**, and will _reject_ other revisions.
+
+## Getting started 
+
+Add "cggtts" to your Cargo.toml
+
+```toml
+cggtts = "4"
+```
+
+Use CGGTTS to parse local files
+
+```rust
+use cggtts::prelude::CGGTTS;
+
+let cggtts = CGGTTS::from_file("../data/dual/GZGTR560.258");
+assert!(cggtts.is_ok());
+
+let cggtts = cggtts.unwrap();
+assert_eq!(cggtts.station, "LAB");
+assert_eq!(cggtts.tracks.len(), 2097);
+```

cggtts/src/lib.rs

@@ -1,4 +1,4 @@
-#![doc = include_str!("../../README.md")]
+#![doc = include_str!("../README.md")]
 #![cfg_attr(docrs, feature(doc_cfg))]
 //! CGGTTS is the core structure, it comprises
 //! the list of tracks (measurements) and some header information.