doc : being more explicit in the synopsis

doc/api/synopsis.md

@@ -9,9 +9,43 @@ Please see the [Command Line Options][] document for information about
 different options and ways to run scripts with Node.js.
 
 ## Example
-
 An example of a [web server][] written with Node.js which responds with
-`'Hello World'`:
+`'Hello World!'`:
+
+Firstly, make sure you have downloaded Node.js from [Node.js Official website](http://nodejs.org/#download).
+Then, follow this [installation guide](https://nodejs.org/en/download/package-manager/).
+
+
+Now, create an empty project folder called `projects`, navigate into it:
+
+Linux and Mac:
+
+```txt
+$ mkdir ~/projects
+$ cd ~/projects
+```
+Windows CMD:
+```txt
+> mkdir %USERPROFILE%\projects
+> cd %USERPROFILE%\projects
+```
+
+Windows PowerShell:
+
+```txt
+> mkdir $env:USERPROFILE\projects
+> cd $env:USERPROFILE\projects
+```
+
+Next, create a new source file in the `projects` folder and call it `hello-world.js`.
+
+If you’re using more than one word in your filename, use an hyphen (`-`) or an underscore(`_`) to separate them for simplicity and avoid using the space character in file names. 
+
+For example, you’d use `hello-world.js` rather than `hello world.js`.
+Node.js files always end with the `.js` extension. 
+
+Open `hello-world.js` in your favorite text editor and paste in the following content.
+
 
 ```js
 const http = require('http');
@@ -22,21 +56,25 @@ const port = 3000;
 const server = http.createServer((req, res) => {
   res.statusCode = 200;
   res.setHeader('Content-Type', 'text/plain');
-  res.end('Hello World\n');
+  res.end('Hello World!\n');
 });
 
 server.listen(port, hostname, () => {
   console.log(`Server running at http://${hostname}:${port}/`);
 });
 ```
-
-To run the server, put the code into a file called `example.js` and execute
-it with Node.js:
+Save the file, go back to your terminal window enter the following command:
 
 ```txt
-$ node example.js
-Server running at http://127.0.0.1:3000/
+$ node hello-world.js
 ```
+you should see an output like this in your terminal to indicate Node.js server is running:
+ ```javascript
+ Server running at http://127.0.0.1:3000/
+ ````
+ Now, open your favorite browser and visit `http://127.0.0.1:3000`.
+
+ You should see the string `Hello, world!`. 
 
 Many of the examples in the documentation can be run similarly.