Add Readme + version 0.0.1

Cargo.toml

 [package]
 name = "pdbparser"
-version = "0.1.0"
+version = "1.0.0"
 authors = ["NOEL Philippe <philippe.noel@inria.fr>"]
 edition = "2018"
 include = ["Cargo.toml", "src/**/*.rs", "tests/**/*.rs", "README.md"]

README.md

+# PDBparser 
+
+**PDBparser is a library written in rust to read and select atoms in protein structure files in the [PDB format](http://www.wwpdb.org/documentation/file-format)**
+
+## Usage
+
+Add this to your `Cargo.toml`:
+
+```toml
+[dependencies]
+pdbparser = { git = "ssh://git@gitlab.inria.fr/pnoel/pdbparser.git" }
+```
+
+and this to your crate root:
+
+```rust
+extern crate pdbparser;
+```
+
+Here's a simple example that read a pdb file in tests/tests_file
+
+```rust
+extern crate pdbparser;
+
+use pdbpaser::*;
+
+fn main() {
+    let my_prot = parse_pdb("tests/tests_file/5jpq.pdb", "5jpq");
+
+    println!("Prot : {} \nn chain: {}\nn res: {}\nn atom: {}",
+    my_prot.name, my_prot.get_number_chain(),
+    my_prot.get_number_residue(),
+    my_prot.get_number_atom());
+
+    println!("Reduce protein");
+
+    let chain_a = my_prot.select_atoms("chain a").unwrap();
+    println!("Prot : {} \nn chain: {}\nn res: {}\nn atom: {}",
+    chain_a.name, chain_a.get_number_chain(),
+    chain_a.get_number_residue(),
+    chain_a.get_number_atom());
+}
+```
+
+## Todo
+
+- [ ] : PDB Writer
+- [ ] : Structure to keep informations on nucleic acid/lipid/water
+- [ ] : More options to select atoms (Alpha carbon, atoms near to an other, ...)
+- [ ] : Support of PDBx/mmCIF format