feat: change Directory highlight group to be blue

[vqvw]

This is a small PR, just to make the Directory highlight group blue. Only a suggestion. The reasoning behind this is to match the colour of directories in the light theme on Github:

Here is how it looks:

I also tried with gray since this is the colour of the directories in Github's dark theme, but it doesn't look quite as good:

Either way, the existing pink colour seems to be a little out of place, in my opinion at least.

[tmillr]

Thanks for the pr and for pointing this out. Might have to give it some thought on what the default should be here. The Directory hl group is primarily meant for directory names, and it's not totally clear if it should apply to directory icons as well. In the wild it seems that some plugins use it for the icon (or rather the icon as well), while others do not (e.g. diffview.nvim). Either way, you're probably right in that it could use a better default. We also have the primitive that is used for (just) the icon on GitHub (e.g. require('github-theme.palette.primitives.light').treeViewItem.directory.fill), but then we're back to square one and it will get used for directory names too as your images demonstrate.

Which plugin is that from?

[vqvw]

Hm, good point. The plugin from the screenshots is oil.nvim, which seems to use Directory for both the directory icon and directory names, but not file names.