file_icons: Associate `.R` files with R (#24907)

5brian and Marshall Bowers created

Closes #24899

Sorted using:
https://github.com/zed-industries/zed/pull/12487#issue-2325944879

Release Notes:

- N/A

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

Change summary

assets/icons/file_icons/file_types.json | 1 +
1 file changed, 1 insertion(+)

Detailed changes