Add installation information for Arch Linux

INSTALLATION.md

@@ -1,9 +1,11 @@
 Installation
 ============
 
+## 1. Dependencies
+
 **Before running the installation script you have to install the dependencies needed for compiling.**
 
-## Kubuntu 16.10
+### Kubuntu 16.10
 
 ```
 sudo add-apt-repository ppa:kubuntu-ppa/backports
@@ -12,9 +14,21 @@ sudo apt dist-upgrade
 sudo apt install cmake extra-cmake-modules qtdeclarative5-dev libqt5x11extras5-dev libkf5iconthemes-dev libkf5plasma-dev libkf5windowsystem-dev libkf5declarative-dev libkf5xmlgui-dev libkf5activities-dev 
 ```
 
-*Now you can run the installation script*
+### Arch Linux
+
+```
+sudo pacman -Syy
+sudo pacman -S cmake extra-cmake-modules
+sudo pacman -S qt5-base qt5-declarative qt5-x11extras
+sudo pacman -S kiconthemes kdbusaddons kxmlgui kdeclarative plasma-framework plasma-desktop
+```
+
+## 2. Building and Installing
+
+**Now you can run the installation script.**
 
-####installation script####
-- _sh install.sh_
+```
+sh install.sh
+```
 
-Latte is now ready to be used by executing  ```latte-dock```
+Latte is now ready to be used by executing  ```latte-dock``` or _Latte Dock_ in applications menu.