Add customizable prefix to the website

[vladfaust]

For example, I often use d- prefix for my projects. It'd be cool if I could specify it in the website settings (saved in local storage), so that I can copy-paste the examples faster!

[pdanpdan]

This is the reason why it was already implemented some time ago. Check the prefix field on each page

[saadeghi]

[vladfaust]

Ah okay, I haven't noticed it, thanks!