Added an explanation

Added an explanation on how to install nodejs on linux(ubuntu).

readMe.md

@@ -164,6 +164,8 @@ I believe you have the motivation and a strong desire to be a developer, a compu
 
 You may not need node.js right now but you may need it for later. Install [node.js](https://nodejs.org/en/).
 
+# Windows
+
 ![Node download](images/download_node.png)
 
 After downloading double click and install
@@ -177,6 +179,14 @@ asabeneh $ node -v
 v12.14.0
 ```
 
+# Linux(ubuntu)
+
+Just type this is your terminal
+
+```sh
+sudo apt install nodejs
+```
+
 When making this tutorial I was using node version 12.14.0, but now the recommended version of node.js for download is 12.17.0.
 
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