Add Git tutorial

[Starlight220]

Articles:

• Introduction
• Create Branch
• Add and Commit - missing 1 images
• Push
• Submit PR
• Reviews
• Rebasing - missing 1 images
• Squash/Merge

Other TODOs:

• Handle SVG linking
• Add menu, vertical sidebar
• Easier access from main menu
• link to k88hudson/git-flight-rules

[NirLevanon]

Who is this for? Definitely not for beginners :)
Very well built and documented, but the question if it fits to be used by the other sub-team members and those to come in the next years, meaning - can they handle this level of English and terminology?

Again, very well documented! 👏

What are the odds someone (other than you) can translate this to Hebrew, as a side-project? This will be very helpful to other teams as well.

Should this really belong in the website project?
If the intention is to add this as a section in the team's website, then I'm actually OK if the .mds can be converted to HTML + CSS - could be a nice project for someone interested in web design (front-end).

[NirLevanon]

Why not add a visual example of how branching looks like, meaning a branching graph. A clear one, where a branching is shown. Don't think showing merge is relevant.

[NirLevanon]

Okay, you can copy the image from the index.

[Starlight220]

I plan to have a whole tutorials section on the website, with tutorials for other subteams too.
The Markdown files are automagically converted to HTML and formatted using CSS, together with some JS magic.

You can run the site locally by cloning, installing Jekyll, and running bundle exec jekyll serve in the project root. See how they're rendered, if there's still formatting changes that you think should be done then tell me.

I totally agree with the need to add some more graphs/diagrams.

About the level of the tutorial, I tried to make it as simple as possible. I don't want to translate it to Hebrew because it loses all the terminology. If you think of anything that can make it more level-appropriate for both current and future subteam members, I'm happy to implement it.

I have an idea:
@korozya-bit - can you go over the content (text, not the HTML elements etc) of the tutorial and see if the level is too high? Mostly the .md files - the content is there. You can also run the website on your computer using the steps I wrote above to see the rendered pages with the formatting and images and everything.

[Starlight220]

IntelliJ 2020.2.3 (released today) changed the Git interface, so if the changes are significant I will redo the IntelliJ sections. This might delay when this is merged.

I might split the core tutorial "framework" stuff to a different PR so it can be merged earlier.