Errors noisily if no "name" is present in budgie.json

[JoshuaKGoldberg]

Following #53, if you have the same reproduction but a budgie.json with {} as its contents, you get this lovely error message:

TypeError: Cannot read property 'length' of undefined
    at NameSplitter.split (C:\Code\budgie-cli\node_modules\budgie\lib\Rendering\Casing\NameSplitter.js:18:38)
    at C:\Code\budgie-cli\lib\postprocessing\metadata.js:20:104
    at Generator.next (<anonymous>)
    at fulfilled (C:\Code\budgie-cli\lib\postprocessing\metadata.js:5:58)