Added a new lesson on GitHub Desktop.

[gauthambrahma]

This lesson primarily targets researchers who are not very found of the terminal to adopt version control using git. It can be a good replacement for some of the lessons after "Conflicts" which are non hands-on.

[rgaiacs]

I think that have a episode about GitHub Desktop goes on the opposite direction of some of our values, specially be inclusive to users of different OS. https://desktop.github.com/ says

Download for macOS or Windows (msi)

so users of Linux would not be able to follow this lesson. If we really want to have a lesson using a GUI for Git I would suggest to write a separate lesson, e.g. https://github.com/swcarpentry/git-novice-gui, and use https://www.gitkraken.com/ or another GUI that supports macOS, Window and Linux. For reference, Git Bash includes an Tcl/Tk based graphical user interface that is part of Git so is available for macOS and Linux.

[munkm]

Thank you for your pull request @gauthambrahma! You've done a lot of work and it looks like you've really thought about the content you'd like to see added.

I agree with @rgaiacs that we want to make sure that we're inclusive to users with different operating systems. I'd like to mention that there have been other issues in this repository that talk about using GUI-based alternatives in this lesson, e.g. #406 and #340

I'd also like to point out that the contributing guidelines for this lesson cautions adding completely new lesson material, i.e. :

Our lessons already contain more material than we can cover in a typical workshop, so we are usually not looking for more concepts or tools to add to them. As a rule, if you want to introduce a new idea, you must (a) estimate how long it will take to teach and (b) explain what you would take out to make room for it. The first encourages contributors to be honest about requirements; the second, to think hard about priorities.

The git lesson certainly tries to cover a lot, and we're intentionally leaving out other important concepts like branching because the lesson is too long already. What would you remove from this lesson to add your new content? Is it worth prioritizing over the content that you're suggesting get deleted? As much as teaching git via a GUI could be really useful, I wonder if is in scope for this particular lesson. I would also second @rgaiacs suggestion that a gui-based lesson could be offered as an alternative to this lesson, so the entire course could be taught with the gui rather than switching from the command-line to the GUI halfway through. Switching midway through the lesson or showing a GUI option at the end might be even more confusing to new learners.

[munkm]

Hi @gauthambrahma. I'm going to close this PR because the concept isn't one we're going to be able to merge into this lesson. Please do keep us updated if you decide to make a variant of the git lesson with github desktop though. 🖥 We'd really like to hear how it goes!