Note that when running a tutorial Rmd file with run_tutorial
the tutorial Rmd should have already been rendered as part of the
development of the package (i.e. the corresponding tutorial .html file for
the .Rmd file must exist).
# NOT RUN {# display all "learnr" tutorialsavailable_tutorials("learnr")
# run basic example within learnr# }# NOT RUN {run_tutorial("hello", "learnr")
# }