Update readme

Author: darcato

README.md

@@ -9,22 +9,25 @@
 ## Installation
 
 ### From extensions.gnome.org
+
 This can be installed from the GNOME extensions webpage:
 
 https://extensions.gnome.org/extension/3061/vlan-switcher/
 
 ### From source code
 
-```
+```bash
 cd ~/.local/share/gnome-shell/extensions/
 rm -r vlan-switcher@darcato.github.io
 git clone https://github.com/darcato/gnome-vlan-switcher vlan-switcher@darcato.github.io
 ```
+
 Now log out and log back in to reload the extensions.
 
 ## Usage
 
 This will let you activate or deactivate existing VLAN connections, managed by the network manager. You first need to create the VLANs with your preferred tool, such as `nm-connection-editor`. The status of each connections is refreshed only when you open the popup menu.
 
 ## License
+
 [GPLv3](http://www.gnu.org/licenses/gpl-3.0.en.html)