feat(cpa): create project from example using --example CLI arg (#10172)

Adds the ability to create a project using an existing in the Payload
repo example through `create-payload-app`:

For example:
`pnpx create-payload-app --example custom-server` - creates a project
from the
[custom-server](https://github.com/payloadcms/payload/tree/main/examples/custom-server)
example.

This is much easier and faster then downloading the whole repo and
copying the example to another folder.
Note that we don't configure the payload config with the storage / DB
adapter there because examples can be very specific.

examples/auth/README.md

@@ -6,20 +6,17 @@ This [Payload Auth Example](https://github.com/payloadcms/payload/tree/main/exam
 
 To spin up this example locally, follow the steps below:
 
-1. Clone this repo
-1. Navigate into the project directory and install dependencies using your preferred package manager:
+1. Run the following command to create a project from the example:
 
-- `pnpm i --ignore-workspace`\*, `yarn`, or `npm install`
+- `npx create-payload-app --example auth`
 
-> \*NOTE: The --ignore-workspace flag is needed if you are running this example within the Payload monorepo to avoid workspace conflicts.
-
-1. Start the server:
+2. Start the server:
    - Depending on your package manager, run `pnpm dev`, `yarn dev` or `npm run dev`
    - When prompted, type `y` then `enter` to seed the database with sample data
-1. Access the application:
+3. Access the application:
    - Open your browser and navigate to `http://localhost:3000` to access the homepage.
    - Open `http://localhost:3000/admin` to access the admin panel.
-1. Login:
+4. Login:
 
 - Use the following credentials to log into the admin panel:
   > `Email: demo@payloadcms.com` > `Password: demo`