Hello spoooopyyy hackers 🎃

This is a Hacktoberfest only issue! 👻

Find our contributing guidelines here, this walks you through how to add a decoder / cracker!
https://github.com/Ciphey/Ciphey/wiki#adding-your-own-crackers--decoders

Don't worry if it looks hard, we will walk you through everything! :)

Write this issue in C++!

Links

These links will help you understand how this works!
https://en.wikipedia.org/wiki/Autokey_cipher
http://rumkin.com/tools/cipher/vigenere-autokey.php