docs(qwik-router): document redirect after POST using PRG pattern

[syrfmy]

What is it?

• Docs / tests / types / typos

Description

Closes #8531
Documents how to avoid the "Confirm Form Resubmission" browser warning when using routeAction$ with native form submissions, using the Post/Redirect/Get (PRG) pattern.
Detects browser submissions via the Accept: text/html header and calls throw redirect(303, ...) to transition to a safe GET request.

Checklist

• My code follows the developer guidelines of this project
• I performed a self-review of my own code
• I added a changeset with pnpm change
• I made corresponding changes to the Qwik docs
• I added new tests to cover the fix / functionality

[changeset-bot]

⚠️ No Changeset found

Latest commit: 81b5092

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[maiieul]

LGTM @syrfmy 👍

[maiieul]

It's still in draft though. Is this good to merge?

[pkg-pr-new]

Open in StackBlitz

@qwik.dev/core

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/core@8922

@qwik.dev/router

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/router@8922

eslint-plugin-qwik

npm i https://pkg.pr.new/QwikDev/qwik/eslint-plugin-qwik@8922

create-qwik

npm i https://pkg.pr.new/QwikDev/qwik/create-qwik@8922

@qwik.dev/optimizer

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/optimizer@8922

@qwik.dev/devtools

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/devtools@8922

commit: 81b5092

[syrfmy]

Yes, sorry i forgot to move it out of draft