update installation instructions (#194)

Author: khassel

getting-started/installation.md

@@ -14,10 +14,9 @@ installers can be found under:
 
 ## Manual Installation
 
-1. Download and install the latest _Node.js_ version:
-
-- `curl -sL https://deb.nodesource.com/setup_18.x | sudo -E bash -`
-- `sudo apt install -y nodejs`
+1. Download and install the latest _Node.js_ version, see the official documentation:
+- [Linux based distributions](https://github.com/nodesource/distributions)
+- [Others](https://nodejs.org/en/download)
 
 2. Clone the repository and check out the master branch:
    `git clone https://github.com/MichMich/MagicMirror`