feat: default project name

[Danil42Russia]

Issue

Now, if you specify an empty name, the name of the folder where create-ton was launched will be implicitly selected as the project name.

I think it's useful, but now I'm clearly stating it:

I also fixed bug #46, where it was possible to specify an empty name for a project. Yes, the current folder is calculated there, but it's a little strange, so it's better to disable this behavior.

Checklist

Please ensure the following items are completed before requesting review:

• Updated CHANGELOG.md with relevant changes
• Documented the contribution in README.md
• Added tests to demonstrate correct behavior (both positive and negative cases)
• All tests pass successfully (yarn test)
• Code passes linting checks (yarn lint)