### What?
This PR introduces a new `--tailwind` flag to the `create-next-app` CLI,
to make it easier to bootstrap a Next.js app with Tailwind CSS
pre-configured. This is going to be the **default**. To opt-out of
Tailwind CSS, you can use the `--no-tailwind` flag.
### Why?
Tailwind CSS is one of the most popular styling solutions right now, and
we would like to make it easier to get started.
Currently, the closest you can come to this is by running `pnpm create
next-app -e with-tailwindcss` which will clone the
https://github.com/vercel/next.js/tree/canary/examples/with-tailwindcss
example. But that example is not configured for the App Router. This PR
will let you add Tailwind CSS to both `app/`, `pages/`, and start out
with TypeScript or JavaScript via the CLI prompts.
(Some community feedback
https://twitter.com/dev_jonaskaas/status/1632367991827443713,
https://twitter.com/samselikoff/status/1634662473331617794)
### How?
We are adding 4 new templates to the CLI bundle.
> Note: The styling is not pixel-perfect compared to the current
templates (using CSS modules) to require fewer overrides, but I tried to
match it as close as possible. Here are a few screenshots:
<details>
<summary><b>Current, light</b></summary>
<img
src="https://user-images.githubusercontent.com/18369201/224733372-9dba86fe-9191-471d-ad9f-ab904c47f544.png"/>
</details>
<details>
<summary><b>Tailwind (new), light</b></summary>
<img
src="https://user-images.githubusercontent.com/18369201/224733610-038d9d0f-634d-4b69-b5c2-a5056b56760c.png"/>
</details>
<details>
<summary><b>Current, dark, responsive</b></summary>
<img
src="https://user-images.githubusercontent.com/18369201/224733790-9b4d730c-0336-4dbe-bc10-1cae1d7fd145.png"/>
</details>
<details>
<summary><b>Tailwind (new), dark, responsive</b></summary>
<img
src="https://user-images.githubusercontent.com/18369201/224734375-28384bbc-2c3a-4125-8f29-c102f3b7aa1d.png"/>
</details>
#### For reviewers
This introduces 4 new templates, with a very similar code base to the
original ones. To keep the PR focused, I decided to copy over duplicate
code, but we could potentially create a shared folder for files that are
the same across templates to somewhat reduce the CLI size. Not sure if
it's worth it, let me know. Probably fine for now, but something to
consider if we are adding more permutations in the future.
---
~Work remaining:~
- [x] app+ts
- [x] layout
- [x] dark mode
- [x] media queries
- [x] animations
- [x] app+js
- [x] pages+ts
- [x] pages+js
- [x] prompt/config
- [x] deprecate Tailwind CSS example in favor of CLI
- [x] update docs
- [x] add test
- [x] add [Prettier
plugin](https://github.com/tailwindlabs/prettier-plugin-tailwindcss)
Closes NEXT-772
Related #45814, #44286
