Added instructions on how to copy the app directory with degit in the getting started tutorial

[Xavier577]

I included a line that describes how to use degit to clone the app directory in the getting started repo.

Proposed changes

Use degit to clone the app directory from the getting-started repo. I did because degit has the ability to clone just the app directory without cloning the entire repo which is more intuisive.

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[Xavier577]

I was editing straight from GitHub but now I had to clone the repo and edit locally because I wanted to change and see my changes and not have to redeploy every time. I was having issues with excessive whitespace but I fixed it up and I think I am good to go, here is a screenshot of my change. Please do leave a feedback.

[craig-osterhout]

Hi @Xavier577, thank you for looking in to this issue. Installing additional apps that are only used in the tutorial can be a touchy point for some users.

We can also use git to pull only the app folder.

    $ git init
    $ git remote add -f origin https://github.com/docker/getting-started.git
    $ git config core.sparseCheckout true
    $ git sparse-checkout set app/
    $ git pull origin master

Alternatively, we can include step-by-step instructions on extracting the folder from the zip file for Mac/Linux and Windows. I think the git steps are probably the better solution because it doesn't require installing additional apps, and it's quick and easy to copy-paste the same instructions for all platforms.

[Xavier577]

Thank you for your feedback @craig-osterhout. I used degit becuase I figured most of the users of docker would most likely have nodejs and npm already installed along with the fact that the tutorial was a nodejs one, plus doing it with degit was just a one line command.Do you suggest add the git way of doing it instead?

[thaJeztah]

I wonder if we should jump through these hoops; the repository shouldn't be too big as a whole, so

git clone https://github.com/docker/getting-started
cd app

doesn't feel too bad to do 🤔

[Xavier577]

yh you are right, it's just that there a number of people who wouldn't want to clone an entire repo just to use one directory. But I just thought it would be more intuisive. 😅

[craig-osterhout]

Thanks again for contributing. Closing this as the consensus seems to be keep it the same.