[Docs] A few standalone examples for prism, say 3 to 5?

[rubyFeedback]

Hey there Kevin,

If you ever have some spare time, do you think you could add a few standalone examples
for using prism? I mean specifically just using prism itself to see how it could be used.

Right now the documentation mentions various other projects that use prism. This is
fine. What I am looking for, though, is how prism could actually be used, from within
.rb files itself.

These examples do not have to be complicated! Really simple examples are fine. They
also don't have to be huge examples either, say 3-20 lines of code should suffice -
this is really just to get a feel for how to use prism itself, such as via a FAQ like
"how to parse this code stored in that example1.rb file". (And also, to compare how
the old way worked, versus prism's new way - but example .rb files are more
important. I would like to see what has changed from a practical point of view here.)

Anyway, thanks for reading this issue request.