docs: update windows powershell commands

[vimode]

What does this PR do?

Updated the windows powershell commands, in powershell a new line is done via backticks(`). The current guide uses commas(,) for new line instead.
The README.md has the correct commands but the README-CN.md has the incorrect command.

Current

docker run -it --rm ,
    --volume /var/run/docker.sock:/var/run/docker.sock ,
    --volume ${pwd}/appwrite:/usr/src/code/appwrite:rw ,
    --entrypoint="install" ,
    appwrite/appwrite:1.0.3

Updated with backticks.

docker run -it --rm `
    --volume /var/run/docker.sock:/var/run/docker.sock `
    --volume ${pwd}/appwrite:/usr/src/code/appwrite:rw `
    --entrypoint="install" `
    appwrite/appwrite:1.0.3

This aligns with the current proper installation instructions given in the README.md.

Related PRs and Issues

This has been discussed in #315
The same issue in the official docs which is updated in a PR at appwrite/docs/#291.

Have you added your change to the Changelog?

This doesn't change the codebase, so I don't think its needed to be added to changelog.

Have you read the Contributing Guidelines on issues?

Yes

[gewenyu99]

I think this exists in README.md, too, right?

Can we have this change in both places?

[vimode]

The code in the README.md uses the correct convention (uses backticks) for new line.

[stnguyen90]

Hey 👋 awesome work on your PR! We've approved your work and it'll be merged soon!

[christyjacob4]

@vimode can you please resolve the conflicts?

[vimode]

@christyjacob4 I have resolved the merge conflicts.

[christyjacob4]

THANK YOU! All changes merged 🥳

Please reach out to me on our Discord server if you would like to claim your Appwrite swags! As a way of saying thank you, we would also love to invite you to join the Appwrite organization on GitHub. Please share your GitHub username with us on Discord.  

You can accept the invite by visiting https://github.com/orgs/appwrite/invitation. By joining our team, you will officially be an Appwrite maintainer on GitHub.

You can change your membership visibility settings, so your new Appwrite team membership badge will show up on your personal GitHub profile.

Please feel free to look for more PRs you might be interested in helping with on our long list of Hacktoberfest friendly issues and help make Appwrite better :)