update psis ref journal info

[avehtari]

update psis ref journal info

[github-actions]

This is how benchmark results would change (along with a 95% confidence interval in relative change) if 9de9857 is merged into master:

• ✔️as_draws_array: 138ms -> 138ms [-0.75%, +0.29%]
• ✔️as_draws_df: 62.8ms -> 62.6ms [-1.67%, +0.88%]
• ❗🐌as_draws_list: 157ms -> 159ms [+0.77%, +2.14%]
• 🚀as_draws_matrix: 61.1ms -> 59.3ms [-3.93%, -1.85%]
• 🚀as_draws_rvars: 82.4ms -> 80.6ms [-3.93%, -0.57%]
• ✔️summarise_draws_100_variables: 710ms -> 709ms [-0.27%, +0.17%]
• ✔️summarise_draws_10_variables: 109ms -> 108ms [-0.74%, +0.51%]
  Further explanation regarding interpretation and methodology can be found in the documentation.

[paul-buerkner]

Thanks!