This scrips takes the argument of a Nextcloud Client AppImage file and installs it in a user-friendly manner.

Specifically, the script:

- Checks file existance
- Moves it to a local assets/ folder
- Updates it's executable permissions
- creates a symlink for the executable at /usr/local/bin/nextcloud
- checks for the existance of a .desktop file in the assets folder
- creats a symlink for the .desktop file at /usr/local/share/applications/nextcloud.desktop