obsidian-cursors: new package

[Thomas:
 - rename from obsidian_cursors to obsidian-cursors
 - change prompt from obsidian to obsidian-cursors in order to match
   with the package name.]

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>