feat(icon): add R language folder icon

[hugosantanna]

Description

Add a dedicated folder icon for the R programming language.

R already has a file icon in this theme, but there is no corresponding folder icon for directories named R/ or r/ — which is the standard convention in R packages and projects (the R/ directory holds all source files in every R package).

Changes

• Added folder-r.svg (closed) and folder-r-open.svg (open)
• Registered folderNames: ['r'] in folderIcons.ts

Icon Design

Uses the official R Foundation logo shape (gray ellipsoid + blue R letter) with flat Material Design colors:

• Ellipsoid: Grey 600 (#757575)
• R letter: Blue 800 (#1565c0)
• Folder background: Light Blue 400 (#42a5f5) — matches existing folder icons

The R logo is positioned to leak out of the folder, consistent with other language folder icons (e.g., folder-python).

The data-mit-no-recolor attribute is set on the R logo group to preserve its colors when cloned.

References

• Official R logo: https://www.r-project.org/logo/ (CC-BY-SA 4.0)
• Closes [Icon Request]: Add folder icon for R language #3386

[github-actions]

Preview

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[lucas-labs]

I've been playing for a bit, trying to make this one align with our guidelines and theme style.

I used #1976d2 for the folder shape (same color the R file icon uses) and #90caf9 for the motive (see Guidelines)

This is what I got (two variations, one with the circle around the R, another without it):

   

Thoughts?

[hugosantanna]

They are amazing! I would love to see those implemented.

[hugosantanna]

I think the one with the circle-ish thing is cool. It should be default.

[SayanShankhari]

i would like erase some portions of the oval touching R and keep it close to official icon by keeping the oval.
In low res, the oval shaped ellipsoid will complement the almost invisible R's round shape.

Like the following,

[PKief]

Nice, it would also prefer this version with the ellipse :)

[hugosantanna]

The ellipse not touching is super nice. I prefer that.

[lucas-labs]

I updated the icons with the new versions.
What do you guys think?

[PKief]

I updated the icons with the new versions. What do you guys think?

I like it, thanks for improving it :)

[hugosantanna]

I like it too! Thank you!

[github-actions]

Merge Successful

Thanks for your contribution! 🎉

The changes will be part of the upcoming update on the Marketplace.