Background changes and changes to installation slides

installation.md

@@ -2,7 +2,35 @@
 
 <img src="img/github_app.png" class="as-is" height="300" />
 
-[mac.github.com](http://mac.github.com) ou [windows.github.com](http://windows.github.com)
+**Linux (Ubuntu)**
+
+```sh
+sudo apt-get install git-all
+```
+<br>
+**macOS**
+
+Install *Xcode Command Line Tools*
+
+<br>
+**Windows**
+
+Follow instructions on *[git-for-windows.github.io](https://git-for-windows.github.io)*.
+
+**or:** `MobaXTerm` with `git` plugin: *[mobaxterm.mobatek.net](https://mobaxterm.mobatek.net)*.
+
+<small>More on *[git-scm.com/book/en/v2/Getting-Started-Installing-Git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git)*</small>
+
+
+## How to start?
+
+**Linux (Ubuntu)** and **macOS**
+
+Start the terminal
+<br>
+**Windows**
+
+Start `GUI Bash` or, if installed, `MobaXTerm`.
 
 
 ## Configuration

list.json

@@ -8,46 +8,55 @@
     {
         "filename": "overview.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "the_terminal.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "what_is_git.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "installation.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "essential_commands.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "github_gitlab.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "branches.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "forks.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     },
     {
         "filename": "thanks.md",
         "attr": {
+          "data-background": "../img/whiteBG.jpg"
         }
     }
 ]