FIX: GIN siblings - fix typo in code and note that --url should not end with .git

[oesteban]

Fixes these minor issues found in the handbook.

[welcome]

(Image: CC-BY license, The Turing Way Community, & Scriberia. Zenodo. http://doi.org/10.5281/zenodo.3332808) Wohoo! 🎉 Thanks for opening your first pull request to the DataLad Handbook! 😎 We really appreciate your time and effort to contribute to the project - you're amazing! 👏

[adswa]

Thanks for catching this, @oesteban!

@mih, I remember this PR came from #706 during the Studyforrest Hackathon, when we created the Gin repos as an alternate datasource in case Juelich's datapub server is offline again at some point. I haven't checked all the studyforrest repos, but I can't find a dataset with a configured special remote to Gin (did we forget to do this somehow?). We maybe want to check if there are datasets configured like this. And if we forgot to configure the datasets, we should probably finally get to it :-)

@all-contributors please add @oesteban for bug .
@oesteban, please feel free to add yourself to the zenodo.json file in the repository.

[allcontributors]

@adswa

I've put up a pull request to add @oesteban! 🎉

[welcome]

(Image: CC-BY license, The Turing Way Community, & Scriberia. Zenodo. http://doi.org/10.5281/zenodo.3332808) Congrats on merging your first pull request! 🎉 The DataLad Handbook team appreciates your contribution greatly, and we want to say thanks! 💖 Now go ahead and share your first merge with your colleagues, you got yourself this brag right! 😄 🎁