If You want to use this snippets in Sonic Pi then You need to

• Clone/download this repository to the $DIR_OF_YOUR_CHOICE
• Add below snippet inside $HOME/.sonic-pi/init.rb file replacing $DIR_OF_YOUR_CHOICE with absolute path:

Linux/Mac OS/Raspberry Pi

load_snippets('$DIR_OF_YOUR_CHOICE/sonic-pi-snippets')

Windows

load_snippets('c:/dir/of/your/choice/sonic-pi-snippets')

From that point snippets should be loaded automagically when Sonic Pi starts.