4.4.1 One of the touch commands has invalid extension

[magmast]

In this part

mkdir -p leapyears/src/leapyears
mkdir -p leapyears/target/public
touch leapyears/target/public/index.html
touch leapyears/src/leapyears/core.cljs
touch leapyears/tools.cljs
touch leapyears/deps.edn

there is a command

touch leapyears/tools.cljs

but should be

touch leapyears/tools.clj

(without "s" at the end).