New practice exercise about Perceptron

[depial]

I have a practice exercise that I could contribute on the Perceptron algorithm. It seems to be a fairly traditional starting point for machine learning study, so I thought it would be appropriate and fun for the Julia track.

I believe I have everything more or less ready to go, but, since this would be my first time contributing, I'm a bit unsure about the process. I've forked the Julia repo, cloned it to my machine where I worked on everything (I used the Anagram exercise as a template for producing the requisite files). The only hiccup so far was that configlet wasn't creating the tests.toml file (it kept saying tests were up to date), so I did that manually using the UUID function. I have pushed them to my fork on GitHub, but I wanted to open an issue before opening a PR, since I figured it was good to see if that is a legitimate way to make the tests.toml file as well as if the exercise is of any interest to begin with.

[depial]

PR opened