Introduce `pkl project init` to create a project aka `PklProject`

[StefMa]

Go has something similar with go mod init.

Creating a PklProject by hand is possible, but I think it would be a nice convenient function to inrtoduce pkl project init.
It will create a PklProject and PklProject.deps.json with some base setup?!

amends "pkl:Project"

package {
  name = "some.name" // Maybe we can support here pkl project init --name "my.awesome.project"
  baseUri = "package://pkg.pkl-lang.org/github.com/[owner/name]/\(name)"
  version = "0.1.0"
  packageZipUrl = "https://github.com/[repo/name]/releases/download/\(name)@\(version)/\(name)@\(version).zip"
  description = "TODO"
  authors {
    "PlaceHolder <author@email.com>"
  }
  website = "https://github.com/[owner/name]"
  sourceCode = "https://github.com/[owner/name]"
  license = "TODO"
  issueTracker = "https://github.com/[owner/name]/issues"
}

dependencies {
  // Add dependencies here
}

{
  "schemaVersion": 1,
  "resolvedDependencies": {}
}

The placeholders and waht we put in should be discussed of course.
But maybe this gives especially new comes a better onboarding to pkl.
No need to find out that it is possible to create a PklProject and how to set it up etc.

We should also discuss if what cli options we support.
name is a good candidate I guess.
website etc. might be a bit too mucy?! 🤔 🤷

[stackoverflow]

This is a really good idea.
We probably need a SPICE to define what will the options be.
Maybe name could be mandatory: pkl project new my-cool-package