Clean up package.json files in the `examples` directory:
- Add `private: true`
- Remove `version` (because they are irrelevant for packages that are not meant to be published)
- Remove `name` (because they are optional for packages that are not meant to be published, and when someone clones an example, they often rename it and the property becomes stale)
- Remove `author`
- Remove `description`
- Remove `license`
Also remove `with-dynamic-app-layout` example completely, since it does the same as `layout-component` (https://github.com/vercel/next.js/pull/27121#discussion_r668178408).
## Documentation / Examples
- [x] Make sure the linting passes
[With next 11 requiring react 17](https://nextjs.org/blog/next-11#upgrade-guide), most of the examples
need to be updated, so the following snippet updated all the examples to
a compatible react version.
```bash
cd examples/
fd -g 'package.json' | xargs sed -r -i 's/"react": ".*"/"react": "^17.0.2"/
fd -g 'package.json' | xargs sed -r -i 's/"react-dom": ".*"/"react-dom": "^17.0.2"/'
# exclude experimental react version
git checkout with-reason-relay/package.json
```
## What
The current `gh-pages` example has issue when deploying.
This is how the error looks like:
```
...
Export successful
The following paths are ignored by one of your .gitignore files:
out
hint: Use -f if you really want to add them.
hint: Turn this message off by running
hint: "git config advice.addIgnoredFile false"
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! next@1.0.0 deploy: `rm -rf node_modules/.cache && next build && next export && touch out/.nojekyll && git add out/`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the next@1.0.0 deploy script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
...
```
It's because `out` folder is added on `.gitignore` and the deploy script runs `git add out/`.
The fix is to remove `out` folder from `.gitignore`.
## How was it tested
run `npm run deploy`, it should be completed successfully.
I wrote a [script](https://github.com/j0lv3r4/dependency-version-updater) to update dependencies recursively in `package.json` files, e.g.:
```
$ node index.js --path="./examples" --dependencies="react=^16.7.0,react-dom=^16.7.0"
```
This PR contains the result against the examples folder.
* Examples: clarify language around Yarn create & npx
* add missing READMEs and create-next-app usage
* suggest people tag jthegedus in firebase related issues
* add yarn alt instructions
* cerebraljs example readme & fixes
