Chore: UX improvements for arguments passing

[mazurroman]

• Add "?" button into the input field (position it to the right). Clicking the button will show a tooltip or a popup with info how to use the arguments, similar to the feat: add support of program arguments #38 PR description. Make sure it works on mobile
• Remove the :focus shadow in the input element, we don't use shadows in this app. Flashing cursor is IMO enough to signal to the user they are inside the input and can start typing

[remybar]

I'm on it !