chore: add spam filter workshop to main repo

[jdwilkin4]

We are using the spam filter project from the JS beta version.

We need to add it to the main repo with steps and tests.

Take a look at the original here
https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures-v8/learn-regular-expressions-by-building-a-spam-filter/step-36

See if there are areas were we can update the tests to use less regex testing and have campers build our more of the functions on their own and accept multiple answers