apt-key is deprecated warning message while installing from script

[LearnLinuxTV]

Due to line 144, a warning will display regarding apt-key being deprecated.

Proposed fix:

• Have the script create the following directory: /usr/share/keyrings
• Change the curl statement that downloads the key to download the key to a local file, such as /usr/share/keyrings/pimox.gpg
• Change the repository URL to become: deb [signed-by=/usr/share/keyrings/pimox.gpg] https://raw.githubusercontent.com/pimox/pimox7/master/ dev/

I will work on a pull request for this issue.