add license

[SkyBulk]

it's a very interesting project!

Would you consider adding a license to this repository to specify under which terms this code can be used or if its possible to consider adding a permissive license?

[insertish]

This isn't a code repository, it's just used to house the discussions board.
Individual licenses can be found under each code repository, i.e. https://github.com/revoltchat/backend/blob/master/LICENSE.