Change default file extension from .r to .R

[py9mrg]

Hello,

Can you please consider changing the default file extension from .r to .R. While in most cases the difference is not important, the most common is the latter and there are some software that expect it - which can be problematic when it's not there.

For example, the starship shell prompt R module: https://starship.rs/config/#r . This expects to find a range of R related files (.R, .Rd, .Rproj etc) but won't work with .r . As there are no uses cases I know of that will work with .r but not .R, it makes sense to use .R as the default.

Thanks.