On http://ninja-ide.org/downloads/ it looks like you have to manually download the package and install in archlinux.
But the ninja-ide 2.0 release is in the official repository so it would be better to add a box like for ubuntu with instructions as there is no need to manually download it. The official packages are signed btw.
The box could be something like that:
For Arch Linux Users:
Ninja-ide is in the community repository of archlinux. Just install it with your package manager:
On http://ninja-ide.org/downloads/ it looks like you have to manually download the package and install in archlinux. But the ninja-ide 2.0 release is in the official repository so it would be better to add a box like for ubuntu with instructions as there is no need to manually download it. The official packages are signed btw.
The box could be something like that:
For Arch Linux Users:
Ninja-ide is in the community repository of archlinux. Just install it with your package manager:
Of course you will get automatic updates then!