Add support for asdf via `.tool-versions` file

[lucianoratamero]

One easy win for people that use asdf would be to create a .tool-versions file in the root directory with the nodejs and python versions.
I've also tested it with pnpm and it worked fine, so adding that could be good too.

Something like:

nodejs lts
python 3.10.10
pnpm 7.28.0