Update README (add methods section)

README.md

@@ -7,7 +7,7 @@ A TypeScript lib that solves Puzzle Game problem using the A* Algorithm
 Use the package manager [npm](https://www.npmjs.com/) to install A* Puzzle Solver.
 
 ```bash
-npm install a-star-puzzle-solver-ts
+npm install a-star-puzzle-solver
 ```
 
 ## How to use
@@ -47,6 +47,42 @@ const aStar = AStarPuzzleSolver;
 const solution = aStar.solvePuzzle(state);
 ```
 
+## Methods
+> This library provides only one method:
+
+### solvePuzzle(initialState)
+> Solves the 8 Puzzle Game with provided initial state.
+
+**Arguments**
+
+| Argument | Type    | Options           |
+|----------|---------|-------------------|
+|`initialState`|*Array of Arrays of Number* | 'Any state possible'|
+
+**Example**
+
+```js
+const state = [
+    [1, 2, 3],
+    [4, 5, 6],
+    [7, 0, 8]
+];
+
+const solution = AStar.solvePuzzle(state);
+```
+
+**Return**
+> This method return an object with: 
+> - 'state' property: last state visited (the goal state)
+> - 'evaluationFunctionValue': an object (wich you can use to access property 'g' that represents the depth traveled)
+> - 'previousNode': another Node object with same properties (that you can use to see expanded nodes and operations applied)
+
+**Obs:**
+- For more examples of how to use, see './examples' folder
+- The goalState considered by the algorithm is:
+
+![](./images/goal-state.jpg)
+
 
 ## Contributing
 Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.