Add more details on library usage

Author: EmberCraze

Diff for: README.md

@@ -1,2 +1,33 @@
 # Rust prefix to postfix
-## This is a prefix to postfix notation converter programmed in rust that uses the shunting yard algorithm
+### A prefix to postfix notation converter programmed in rust that uses the shunting yard algorithm
+
+## Usage
+1. Place the library inside your project, in this case test_rust_prefix_to_postfix. Then add rust_prefix_to_postfix = {path = "rust_prefix_to_postfix to the dependencies like below
+```
+[package]
+name = "test_rust_prefix_to_postfix"
+version = "0.1.0"
+edition = "2018"
+
+
+[dependencies]
+rust_prefix_to_postfix = {path = "rust_prefix_to_postfix
+```
+2. Use call the trait in the library and add a new infix operation 
+```Rust
+use rust_prefix_to_postfix::Operation;
+
+fn main() {
+    let op_info_r = rust_prefix_to_postfix::OperationInfo::new(&"122+((2^2)*3-1)-(2^2)+2-sqrt(5*7+3)".to_string());
+
+    if op_info_r.is_ok() {
+        let mut op_info = op_info_r.unwrap();
+        match op_info.reverse_polish_parsing() {
+            Err(e) => println!("{:?}", e),
+            Ok(_) => (),
+        };
+        println!("{:?}", op_info.infix);
+        println!("{:?}", op_info.reverse_pn);
+    }
+}
+```