insertNode of the javascript library method not working correctly

- __InsertNode method__ works __ok if the index passed is 0__ but __not__ when the __index is something else__.

- __Index Check is not working__ since it don't return false on unspecified index in the list.
```
if (index > 0 && index > this.size) {
return false;
} else { ... }
```

- __Commit__ eb3a682780755ef7bb581d664f48d502700fa576
- :deciduous_tree: [__Branch__](https://github.com/khushalbhardwaj-0111/Data-Structures/tree/linked_list_js)