Positron support for book project creation

[cderv]

Creating bs4_book in positron does not work because of using rstudioapi unknown function

> bookdown::create_bs4_book("../bug")
Error:
! Function initializeProject not found in RStudio
Hide Traceback
    ▆
 1. └─bookdown::create_bs4_book("../bug")
 2.   └─bookdown:::activate_rstudio_project(path)
 3.     └─rstudioapi::initializeProject(dir)
 4.       └─rstudioapi::callFun("initializeProject", path)

We should work on supporting Positron. It should be supported in some way

• Epic: rstudioapi Support in R posit-dev/positron#1542

So maybe somethings are missing there too