Update the quickstart.md docs

[Shivam7-1]

What article on docs.github.com is affected?

https://github.com/github/docs/blob/main/content/actions/quickstart.md

What part(s) of the article would you like to see updated?

Additional information

Update some typos on quickstart.md

[welcome]

Thanks for opening this issue. A GitHub docs team member should be by to give feedback soon. In the meantime, please check out the contributing guidelines.

[Shivam7-1]

#241

[janiceilene]

Thanks for opening the issue @Shivam7-1! Closing this with the listed PR.