The code of conduct and contributing are not added

[chemben17]

Both the code of conduct and contributing guidelines are not added to the root directory.
I can work on them.

[mattpocock]

Thanks - though this project is open source, I'm unlikely to merge PR's on the content unless they're quality-of-life upgrades - since the content is here to serve https://www.totaltypescript.com/tutorials/beginners-typescript