Rename from master to main

[kephale]

Just noting that SNT should rename the primary branch of the repo form master to main in order to match the current social standards.

[tferr]

Thanks a lot @kephale . Had completely forgotten about this. @carshadi, here are the instructions to rename your local repo, in case you get stuck on some weird state:

git branch -m master main
git fetch origin
git branch -u origin/main main
git remote set-head origin -a

We should also add a code of conduct and contribution guidelines. Do let me know if you guys have good templates.