Rewriting the Git tutorial to cover less content

["Julia Evans" <julia@jvns.ca>]

Hello!

I'm working on a patch series to replace `gittutorial.adoc` with a completely
rewritten tutorial, since a lot has changed since it was originally written.

The new tutorial will cover much less material: just `git init`, `git add`,
`git commit`, `git status`,  `git diff`, `git push`, `git config`, and `git remote add`. 
One choice that might be controversial is that I'm not covering branches, 
though I think it would probably make sense to write a second tutorial on
branches and using Git to collaborate later.

The reason to cover fewer commands is that even this smaller set of commands
is a lot for beginners to absorb. I've already gotten feedback from a test
reader that they appreciated the "you can stop here!" in the middle of the
tutorial, since they didn't feel like they could absorb any more information at
that point.

If you'd like, you can read the current draft here: 
https://github.com/jvns/git/blob/git-tutorial/Documentation/gittutorial.adoc
I'm not looking for detailed feedback at this stage since I expect a lot of
the details to change, and since right now I'm prioritizing feedback from Git
beginners who are trying to learn Git for the first time from the tutorial.

But if folks have major objections to the high-level structure, let me know!

I'm excited about this direction, I've already gotten some positive feedback from
test readers, like:

> I can say I liked this tutorial better than any of the other git tutorials I've tried.

and

> I really like the tutorial, it's easy to follow and I learned a lot!

I have some ideas for what to do with `gittutorial-2` too but I'll leave
that for another discussion.

thanks!
Julia