This isn't actually open source until you add a license. I personally favor the GNU AGPLv3+ as the one license that requires that any derivative use of your code continue spreading the freedoms to others (by keeping the same license terms). But there are some arguments for more loose licenses that allow anyone to do anything (including make restricted, non-open derivatives), so MIT is the most popular there.
This isn't actually open source until you add a license. I personally favor the GNU AGPLv3+ as the one license that requires that any derivative use of your code continue spreading the freedoms to others (by keeping the same license terms). But there are some arguments for more loose licenses that allow anyone to do anything (including make restricted, non-open derivatives), so MIT is the most popular there.
https://help.github.com/articles/adding-a-license-to-a-repository/