Update 'README.md'

README.md

@@ -1,5 +1,7 @@
 # Intro to Java
 
+## Basic
+
 ```java
 class HelloWorld{
 	void main(String[] args){
@@ -8,6 +10,8 @@ class HelloWorld{
 }
 ```
 
+## Variables
+
 ```java
 String greeting = "Hello there!";
 ```
@@ -21,6 +25,8 @@ int myNewAge = myAge + 2;
 double myWeight = 144.5;
 ```
 
+## Flow of Control
+
 ```java
 Boolean isCool = false;
 if(isCool){
@@ -44,11 +50,15 @@ for(int i = 0; i < 5; i++){
 }
 ```
 
+## Arrays
+
 ```java
 String[] cars = {"Volvo", "Toyota", "Mazda"};
 System.out.println(cars[1]);
 ```
 
+## Functions
+
 ```java
 class HelloWorld{
 	void printMessage() {
@@ -74,6 +84,8 @@ class HelloWorld{
 }
 ```
 
+## Classes
+
 ```java
 class Human {
 	String name;
@@ -90,6 +102,8 @@ class HelloWorld{
 }
 ```
 
+## Inheritance
+
 ```java
 class SuperHuman extends Human {
 	private String power;
@@ -113,6 +127,7 @@ class HelloWorld{
 }
 ```
 
+## Abstract/Interface
 
 ```java
 abstract class Car {