Add timezone client-hints

[rajeshg]

Full credits to @kiliman for this work. https://github.com/kiliman/epic-stack-time-zone

Client hints for timezone are a nice add. The approach is similar to the way themes are handled currently. CH-time-zone will be added to the cookies.

Test Plan

Checklist

• Tests updated
• Docs updated

Screenshots

[kentcdodds]

I love this. Just a few changes.

[kentcdodds]

In this case, we don't need to transform the value at all and the fallback is already defined. I think we should not require the transform function. So let's remove it here.

Suggested change

	transform(value: string | null) {
	return value ?? 'UTC'
	},

This change may necessitate a small update in the code below.

[rajeshg]

We lose some type-checking here. But couldn't think of a better way to do it.

[kentcdodds]

Ah yeah, we'll need to figure out how to have our cake and eat it too here 😅 If you can't work it out, then that's fine. I'll come back to this later when I find time. Thanks!

[rajeshg]

Couldn't figure out :(

[kentcdodds]

Why was this PR closed? I'd still like to have this feature eventually and I'd prefer you get git credit for your work :)

I might recommend you make any future PRs from a non-main branch though.

[rajeshg]

My mistake. You are right, I should have done that from a non-main branch. I attempted to copy over the latest changes from epicweb-dev/epic-stack to rajeshg/epic-stack.

[rajeshg]

Couldn't reopen this myself, since I lack the rights to reopen pull requests on this repo. I will submit a separate pull request, when I get a chance.

[kentcdodds]

I can't reopen it either because you created it from main and now your main branch is different. This is another reason using a different branch helps 😅 Thanks!