[R-pkgs] gsDesign 3.5.0 is released

[Nan Xiao]

Dear all,

I'm thrilled to announce that a new version of gsDesign (3.5.0) is now on CRAN (https://cran.r-project.org/package=gsDesign). gsDesign supports group sequential clinical trial design, largely as presented in Jennison and Turnbull (2000).

The 3.5.0 update introduces some significant enhancements:

- New toInteger() function to convert gsDesign or gsSurv objects to integer sample size and event counts.
- New toBinomialExact() function to convert time-to-event bounds to exact binomial for studies with low event rates.
- New vignette on the fundamentals of asymptotics for group sequential design, and another vignette on the sequential probability ratio test for a single arm binary endpoint.

We have also improved compatibility with the latest ggplot2 version and have introduced a new hex sticker logo. For the complete list of updates, please see the changelog (https://keaven.github.io/gsDesign/news/).

Best regards,
-Nan