Merge pull request #4 from NickNaso/docs

improved documentation and fix on include_dir.

README.md

@@ -3,15 +3,69 @@
 - **[Introduction](#introduction)**
 - **[Contributing](CONTRIBUTING.md)**
 - **[Code of Conduct](CODE_OF_CONDUCT.md)**
+- **[Install](#install)**
+- **[API](#api)**
 - **[Team](#team)**
 - **[License](#license)**
 
+## Current Node-API version: 8
+
+(See [CHANGELOG.md](CHANGELOG.md) for complete Changelog)
+
 <a name="introduction"></a>
 
 ## Introduction
 
-The **node-api-headers** moldule contains the header files for the C based 
-Node-API provided by Node.js.
+**node-api-headers** contains the header files for the C-based Node-API
+provided by Node.js. Node-API is an API for building native addons that
+guarantees the ABI (Application Binary Interface) stability across versions
+of Node.js (see: [Node-API](https://nodejs.org/dist/latest/docs/api/n-api.html)).
+
+Node-API headers are in the `include` folder. The Node-APIs that provide
+ECMAScript features from native code can be found in `js_native_api_types.h`
+and `js_native_api.h`. The APIs defined in these headers are included in
+`node_api_types.h` and `node_api.h`.
+The headers are structured in this way in order to allow implementations of
+Node-API outside of Node.js considering that for those implementations the
+Node.js specific APIs may not be applicable.
+
+**node-api-headers** is also a package published on **npm** that could be used
+in a process to compile and build native addons for Node.js.
+
+<a name="install"></a>
+
+## Install
+
+```
+npm i node-api-headers
+```
+
+<a name="api"></a>
+
+## API
+
+The module exports two properties `include_dir` and `symbols`.
+### `include_dir`
+
+This property is a string that represents the include path for the Node-API
+headers.
+
+### `symbols`
+
+This property is an object that represents the symbols exported by Node-API
+grouped by version and api types.
+
+```js
+    V1: {
+        js_native_api_symbols: [
+            // List of symbols in js_native_api.h for the version 1.
+        ],
+        node_api_symbols: [
+          // List of symbols in node_api.h for the version 1
+        ]
+    },
+   // ...
+```
 
 <a name="team"></a>
 

index.js

@@ -3,7 +3,7 @@
 const path = require('path');
 const symbols = require('./symbols')
 
-const include_dir = path.relative('.', __dirname, 'include');
+const include_dir = path.resolve(__dirname, 'include');
 
 module.exports = {
     include_dir,