set aboslute path to parent of setup.sh

[airtonix]

fixes #125

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before:

> pwd
/home/me/Projects/Mine/Github/Dotfiles

> git clone --depth=1 https://github.com/adi1090x/rofi.git ./windowmanagers/files/rofi

> ./windowmanagers/files/rofi/setup.sh

[*] Installing fonts... 
cp: cannot stat '/home/me/Projects/Mine/Github/Dotfiles/fonts/*': No such file or directory
[*] Updating font cache...
 
[*] Creating a backup of your rofi configs... 
[*] Installing rofi configs... 
cp: cannot stat '/home/me/Projects/Mine/Github/Dotfiles/files/*': No such file or directory
[!] Failed to install.
 

after:

> ./windowmanagers/files/rofi/setup.sh                                               

[*] Installing fonts... 
[*] Updating font cache...
 
[*] Creating a backup of your rofi configs... 
[*] Installing rofi configs... 
[*] Successfully Installed.

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https://stackoverflow.com/a/9107028