NodeJS Controllers: Update lesson to flow with the previous lesson

[fcasibu]

Because

Doesn't flow well enough with the previous lesson and includes passive tone in writing.

This PR

• Make the lesson flow with the routes lesson, to use author example.
• At the very least improve the tone (not that good of an english speaker 😢 so not confident with this but will try to do another re-read)

Issue

Closes #28530

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[MaoShizhong]

Many thanks for working through the feedback!

Some initial comments - I haven't had the time to look at the error handling section and beyond, so I'll get to those in due course (as well as the Routes lesson changes I mentioned).

[MaoShizhong]

Whew! Amazing work. Just a few more small things and a small merge conflict due to #28858 but otherwise I'm happy to merge this along with the Routes changes PR when that's also approved.

[MaoShizhong]

Looking through the rest of the curriculum, it actually looks like most of the time we use function declarations. Nit but for the sake of consistency, I think the functions in this lesson should be func decs unless they're callbacks defined inline (e.g. asyncHandler callback).

Suggested change

	const getAuthorById = async (authorId) => {
	return authors.find(author => author.id === authorId);
	};
	async function getAuthorById(authorId) {
	return authors.find(author => author.id === authorId);
	};

[fcasibu]

done with changing most functions

[MaoShizhong]

Amazing work as always 🙏 Just the one grammar nit but otherwise I'm happy with this and will merge together with #28763 when that's approved.