## Description
This PR ensures that the default prettier config is used for examples
and templates.
This config is compatible with `prettier@3` as well (upgrading prettier
is bigger change that can be a future PR).
## Changes
- Updated `.prettierrc.json` in root with `"trailingComma": "es5"` (will
be needed upgrading to prettier@3)
- Added `examples/.prettierrc.json` with default config (this will
change every example)
- Added `packages/create-next-app/templates/.prettierrc.json` with
default config (this will change every template)
## Related
- Fixes#54402
- Closes#54409
## History
We used to pass `onLoad` through directly to the underlying img so `onLoadingComplete` was introduced in order to handle the case when `placeholder="blur"` was used and `onLoad` would trigger before the placeholder was removed.
We have since changed the behavior of `onLoad` so that it acts the same as `onLoadingComplete` and therefore `onLoadingComplete` is no longer needed.
## What is this PR doing?
This PR marks `onLoadingComplete` as deprecated in favor of `onLoad`. In the future, we may remove `onLoadingComplete`.
