feat(feline): fix feline integration

[89iuv]

This PR is intended to fix the feline integration by:

• changing the background color from mantle to surface0 which is the actual color used in the pictures
• enable the user to use the setup function without any parameter as described in the documentation

Visual changes:
Old:

New:

Reference:

[sgoudham]

We're using crust bars across VSCode/JetBrains now afaik so I believe the picture should be updated instead of reverting back to surface0

[sgoudham]

As mentioned above, the neovim screenshot should be updated to have the crust bar

[89iuv]

Lookin at the VScode repo i see that we are using Crust for the status bar, not mantle.

The problem that i am trying to fix is that in nvim the status bar and the file explorer have the same background color making them blend on into the other and not providing a clear visual distinction between the two of them.

I think if we want to keep consistency across catppuccin editors then maybe crust would be a better fit:

[sgoudham]

Ah yes, good catch! Crust sounds good for consistency with VSCode. @89iuv

[sgoudham]

Thanks for updating the colours, don't want to block the merge on screenshots so we can update them at a later time 👍