Added intro article

.gitignore

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+.idea

00-intro/README.md

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+# Installation
+
+* Official website - https://nodejs.org/en/
+
+![Image](https://nimbus-screenshots.s3.amazonaws.com/s/d404c40261ff6d4be5e1ec49437beac4.png)
+
+* Check installed version of Node.js
+
+Terminal:
+```zsh
+ihor.ostapchuk@ihorostapchuk:~$ node -v
+v12.16.2
+```
+
+* Check installed version of Node Package Manager (NPM)
+
+Terminal:
+```zsh
+ihor.ostapchuk@ihorostapchuk:~$ npm -v
+6.14.4
+```
+
+* First Hello World
+
+File: [hello.js](hello.js)
+```javascript
+console.log('Hello', process.argv[2]);
+```
+
+Terminal:
+```zsh
+ihor.ostapchuk@ihorostapchuk:~$ node hello.js World!
+Hello World!
+```
+
+---
+
+#### *80lvl: Node.js version management - (https://github.com/nvm-sh/nvm) or https://github.com/tj/n
+
+Terminal:
+```zsh
+ihor.ostapchuk@ihorostapchuk:~$ nvm use stable
+Now using node v12.16.2 (npm v6.14.4)
+ihor.ostapchuk@ihorostapchuk:~$ nvm use v10.18.1
+Now using node v10.18.1 (npm v6.13.4)
+```
+

00-intro/hello.js

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+console.log('Hello', process.argv[2]);