added first code about ownership

presentation/library/Cargo.toml

+[package]
+name = "library"
+version = "0.1.0"
+authors = ["Orestis Malaspinas <orestis.malaspinas@hesge.ch>"]
+edition = "2018"
+
+[dependencies]

presentation/library/src/main.rs

+fn do_something(library: Vec<&str>) {
+    // Do something with the library
+}
+
+fn main() {
+    let mut library = Vec::new();
+
+    library.push("Les fleurs du Mal.");
+    library.push("Rust Programming.");
+
+    do_something(library);
+    do_something(library); // redo something
+}