Let's change the existing setting "editor.inlineSuggest.syntaxHighlightingEnabled" to be true

I do not think this is urgent, but we could look into this Feb+?

JetBrains just shipped this feature and I like their transparency / color ratio https://blog.jetbrains.com/ai/2024/10/complete-the-un-completable-the-state-of-ai-completion-in-jetbrains-ides/#highlighting-instead-of-gray-text

fyi @alexdima @bamurtaugh