Added recommended Git Attributes file

I added the Git Attributes which will normalize all line enddings in the binary of all text files. (The enddings are different for linux, windows, mac, etc.) It's kinda sorta pointless, but it's a nice perk Git offers, so why not have it? It also provides a bunch of other things not really needed for this repo.

I also added basic operating system junk files to the gitignore (because they were going to be committed)