This adds a lint rule to ensure we don't import dev dependencies by accident.

fix #12136 

I add a prompt if there is an error when trying to download example files.
Maybe could be better to add an error class and in create-app.ts on every "console.error" trow a new Exception and manage it in catch. What you think ? 👯 

* Support top-level GitHub repo URLs

Adds support for top-level GitHub repo URLs, e.g.
https://github.com/username/my-cool-next-example.

This is already possible, but you have to enter "/tree/master" (or the
desired branch name) after the repo URL.

The change itself simply expands that URL to
https://github.com/username/cool-next-example/tree/$DEFAULT_BRANCH_NAME
where DEFAULT_BRANCH_NAME is the default branch configured for the repo
in GitHub.

* Fix formatting issues

* Initial support for URLs

* Added folder support

* Added --example-path

* Bug fix

* Also install deps

* Updated error message

* Bug fix and replace the file path

* Added tests
Co-authored-by: NShu Uesugi <shu@chibicode.com>

* Rename to README-template.md

* Add yarn scripts

* Rewrite CNA README

* Forgot zeit link

* Simplify

* Update deploy doc

* Just link to the doc

* page is reloaded

* reload → update

* Deploy updates

* Initialize Git repo on app creation
This PR initializes a Git repository after Create Next App runs.

We ensure the app was not created in an already-existing Git or Mercurial repo.

Failures of setup (no Git installed) do not fail the application bootstrapping.

Closes #9077 (replaces)

* Add test

* Update index.test.js

* Completely rewrite Create Next App

* Sort imports

* Show what package manager is being used

* Fix project name suggestion

* Update tests for new implementation

* Use normal prepublish command for on-install

* Upgrade Node version

* Switch to 8.16

* Disable v8 cache

* Swap out update check package and fix CLI boot