While I think the link @Tamas_Papp has pointed is worth reading. I would like to be a little more specific and less overwhelming, and just point that for documentation, you can just be logged into your Github account, go to julia/punctuation.md at master · JuliaLang/julia · GitHub and click the small pencil that has a hovertext of “Fork this project and edit the file”. After this you will be making the changes in your version of the julia repository, and there will be a button somewhere to do a pull request, that is kinda of offering the changes you made in your fork (i.e., copy of the repository) to the original repository you forked. The Julia developers will be notified, they may ask some changes (that you can do by editing the file in your fork by the Github interface) and then they will aprove it and it will be merged to the original/official Julia repository.