![Screenshot on VS Code](https://user-images.githubusercontent.com/12539/96300300-43fc1280-1030-11eb-89ae-dba8beeca583.png)

The only attribute that must be used with Image Component is src, but all attributes are required and TypeScript will warn you.

Unify the confusing `config.images.sizes` ([Image Optimizer](https://github.com/vercel/next.js/discussions/17141)) and `config.images.breakpoints` ([Image Component](https://github.com/vercel/next.js/discussions/16832)).

Image Optimizer only accepts the name of the width parameter as a `w`.

ref https://github.com/vercel/next.js/blob/v9.5.6-canary.3/packages/next/next-server/server/image-optimizer.ts#L71

Co-authored-by: NSteven <steven@ceriously.com>

Co-authored-by: NJJ Kasper <jj@jjsweb.site>

This makes sure the correct `initialRevalidateSeconds` field is populated in the `prerender-manifest` for non-dynamic SSG pages since they will be inserted into the `initialPageRevalidationMap` under their locale prefixed variant with `i18n` enabled

x-ref: https://github.com/vercel/next.js/pull/17370

This PR adjust the Web Vitals reporting to be called *after* rendering occurs. It used to work like this, but React's render method is no longer synchronous—so we have to do it in an effect.

Existing tests should cover this code path, and IMO it's unfeasible to test that it's invoked _after_ hydration.

Also removed the `&& ST` condition which is not relevant to Web Vitals.

* Ensure i18n support with AMP

* Fix type error

* Update size-limit

This adds the i18n config items to the routes-manifest so that they can accessed in the builder. This doesn't increment the routes-manifest version as existing value shapes haven't been modified and an additional non-breaking value is being added

x-ref: https://github.com/vercel/next.js/pull/17370

Co-authored-by: NTim Neutkens <tim@timneutkens.nl>
Co-authored-by: Nkodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

This adds the `locale` prop for `next/link` to allow transitioning between locales client-side and also allows passing the locale to `router.push/replace` via the transition options similar to `shallow` e.g. `router.push('/another', '/another, { locale: 'nl' })`

x-ref: https://github.com/vercel/next.js/pull/17370

This updates to set the `NEXT_LOCALE` cookie to the default locale when the user prefers a different locale from the default in their `accept-language` header but visits the default locale path e.g. `/en-US` with a `accept-language` preferred header of `nl` will set the `NEXT_LOCALE=en-US` header and then redirect to `/`

x-ref: https://github.com/vercel/next.js/pull/17370

Co-authored-by: NLuis Alvarez D <luis@vercel.com>
Co-authored-by: NTim Neutkens <tim@timneutkens.nl>

Co-authored-by: NTim Neutkens <timneutkens@me.com>
Co-authored-by: NTim Neutkens <tim@timneutkens.nl>

Co-authored-by: Nkodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Co-authored-by: NJJ Kasper <jj@jjsweb.site>
Co-authored-by: Nkodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Noticed there's an extra backslash in the example which causes an error. 

**EDIT:**

Also the promise needs to be resolved using `.toString()` before it can be returned as `content` in props.

Related issue: https://github.com/vercel/next.js/issues/10647#issuecomment-623703149

Sometimes we have both Yarn and NPM installed and want to explicitly bootstrap an app with the CLI using NPM. Having this flag documented could help people understand the package manager behavior and select NPM if that's their preference.

Fixes https://github.com/vercel/next.js/issues/17828.

This change adds a caveat to both the "Custom `App`" and "Custom `Document`" pages about how both `getStaticProps` and `getServerSideProps` aren't supported.

`higherOrderComponent(WrappedComponent)` causing the layout broken in mobile screen. 
* refer to screenshots below.


![image](https://user-images.githubusercontent.com/43801058/95730641-faaa6c80-0c97-11eb-9951-2a47b61cefad.png)
![image](https://user-images.githubusercontent.com/43801058/95730661-0138e400-0c98-11eb-9f02-b4d0676fd21b.png)

if we could make it `HOC(WrappedComponent)` it will not break the layout in mobile screen
![image](https://user-images.githubusercontent.com/43801058/95730673-04cc6b00-0c98-11eb-8782-2fa1f760f8fd.png)

Co-authored-by: NTim Neutkens <tim@timneutkens.nl>
Co-authored-by: NTim Neutkens <timneutkens@me.com>

## Change

To opt-in to using the new layers mode by default.

## Motivation

- Reduces CSS filesize
- Prevents users from using the already deprecated old layers mode
- Removes the following console warnings:

```log
risk - There are upcoming breaking changes: purgeLayersByDefault
risk - We highly recommend opting-in to these changes now to simplify upgrading Tailwind in the future.
risk - https://tailwindcss.com/docs/upcoming-changes
```

[more info](https://tailwindcss.com/docs/upcoming-changes)

While working on https://github.com/vercel/next.js/pull/17755 noticed a couple of cases that needed fixing and broke them out to this PR to make that one easier to review. One fix is for `ssgCacheKey` where it wasn't having the `locale` prefix stripped correctly due to the locales no longer being populated under the server instances `renderOpts` and the second fix is for the `asPath` not being set to `/` when the `locale` is the only part in the URL e.g. `/en` became an empty string `""`

x-ref: https://github.com/vercel/next.js/pull/17370

Follow-up to https://github.com/vercel/next.js/pull/17370 this makes sure the locale detection is case-insensitive. 

### Description

Easy navigation and easy reading for others.

A URL is correct, not An URL

Follow-up to https://github.com/vercel/next.js/pull/17370 this adds mapping of locales to domains and handles default locales for specific domains also allowing specifying which locales can be visited for each domain. 

This PR also updates to output all statically generated pages under the locale prefix to make it easier to locate/lookup and to not redirect to the default locale prefixed path when no `accept-language` header is provided.