Figure out what to do with the wasp ts-setup command for Wasp's TS config

[sodic]

When we released the Wasp TS config as an experimental feature, we added a wasp ts-setup command to prepare the project for using the TS config.

Currently (as of 0.15.2), the command doesn't do much.

To properly set up a project that uses the TS config, it's necessary to go through the steps described in the docs, and wasp ts-setup currently only covers two of them.

All the steps are:

• Rename and create new tsconfig.json files.
• Potentially add type: module to package.json.
• Rename main.wasp to something else.
• Run wasp ts-setup
  • It adds the wasp-config package to your package.json's devDependencies.
  • It then runs npm install
• Create an empty main.wasp.ts file and start writing inside.

What we should do:

• Let new users choose what they want to use (Wasp or TS) when creating a new project.
• Let old users migrate more easily, by improving the wasp ts-setup command to do everything or by detecting that the user wants to use the TS SDK by looking for main.wasp.ts (which is tricky due to the way wasp start is set up).

Context:

• TS SDK Setup #2299 (comment)