markdown-dungeon Bambam320 branch

Hi, this is my first open source contribution. I love the project and would like to add a dungeon floor for the year 1500 in the time machine dungeon. It's going to include meeting famous characters from the renaissance and learning some interesting facts about that time in history then returning home with a new perspective on life. I believe I am following the rules but please let me know if I did something incorrectly. I would also appreciate any advice you have, I'm trying to include open source work on my resume to boost its attractiveness.

This pull request includes a change to the begin-journey.md in the time-travel dungeon and the addition of a folder floor and a few rooms. I hope this is done correctly so I can continue to add to it.

Thank you in advance!