* Added trizen to the archlinux plugin

trizen is the recomended solution for using the Arch User Repository.
both yaourt and pacaur have some issues.

Signed-off by: Arthur Brainville (Ybalrid) <ybalrid@ybalrid.info>

* Add trizen aliases to the readme

Also fixed inconsistency in formatting on readme file.
(also added myself in the contributor list)