docs: change examples in docs to use for..of and async/await (#14842)

[AbhilashJN]

Description of Change

Changed code examples in desktop-capturer.md and using-selenium-and-webdriver.md to use for..of and async/await instead of normal for loop and Promises.
CC @ckerr @codebytere

Checklist

• PR description included and stakeholders cc'd
• relevant documentation is changed or added
• PR title follows semantic commit guidelines

Release Notes

Notes: docs: update some examples in documentation to use async/await and for..of

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[BinaryMuse]

I wonder if this example would be a little more clear if we made this a named async function instead of an IIFE. Thoughts? 💭

[AbhilashJN]

Sure that would be better. Will update.

[BinaryMuse]

It looks like we use async/await elsewhere, I'd be 👍 for this change

[BinaryMuse]

Based on the PR title, I assume this should be of :)

Suggested change

	for (const source in sources) {
	for (const source of sources) {

[AbhilashJN]

Whoops!

[release-clerk]

Release Notes Persisted

docs: update some examples in documentation to use async/await and for..of

[welcome]

Congrats on merging your first pull request! 🎉🎉🎉

[BinaryMuse]

Thanks @AbhilashJN!