[RRFC] npm init should also initialise git repo if it git is installed or the folder is not a git repo already

Motivation ("The Why")

• Most of the time when developers do $ npm init in a project they usually run $ git init to set it as a git repo
• In other eco systems like Rust in tools like cargo when you do cargo init checks if you have git installed if so initialises it as a git repo (it it already not a git repo)
• If the developer does not want to use git but use other version controls (or none) they could specify it in a flag like
  $ cargo --vcs
• We could do similar thing in npm. Even-though this is not a major change it does improve the developer experience little bit

Example

• You go to a folder and run $ npm init -y it creates a package.json with default values and also initialises it as a git repo

How

Current Behaviour

• Right now when you do $ npm init it asks you a set of questions then it initialises the package.json
• Or when you do $ npm init -y it creates the package.json with default values

Desired Behaviour

• When you run $ npm init ask question about version control (with git as default value)
• Similarly when they run $ npm init -y it will create package.json and initialise the folder as git repo if it is already not a git repo and git is installed

References

• n/a

Start by reviewing the npm init and npm init -y entry points and compare their current question flow and package.json creation behavior with git init availability and repository detection. Resolve the proposed version-control prompt and flag behavior before implementation; done means the agreed behavior is documented and covered for existing repositories, missing git, and noninteractive -y runs.