Add notes to video tutorial links

[davidwilby]

For instance, the video tutorial for installing git on windows (from SWC) also details installation of nano using a SWC installer, which isn't required for this workshop.

In fact, is gitbash even required for gitkraken? Even if it's not I think it's nice to leave participants with git installed on whatever OS.

@annakrystalli @ns-rse @bobturneruk happy to discuss.

[bobturneruk]

I think the video link here https://srse-git-github-zero2hero.netlify.app/setup/git/ should go. I'd like to maximise the chance that all learners will set up consistently.

The note here https://srse-git-github-zero2hero.netlify.app/setup/gitkraken/ says git is not needed for gitkraken, but makes good points about use after the lesson, so maybe make it optional?