Add allowSyntheticDefaultImports = true

Because of validateNPMPackageName.
Otherwise,

```
14 import validateNPMPackageName from "validate-npm-package-name";
          ~~~~~~~~~~~~~~~~~~~~~~

  node_modules/@types/validate-npm-package-name/index.d.ts:29:1
    29 export = validate;
       ~~~~~~~~~~~~~~~~~~
    This module is declared with 'export =', and can only be used with a default import when using the 'allowSyntheticDefaultImports' flag.

Found 1 error in index.ts:14
```

tsconfig.json

@@ -4,6 +4,7 @@
     "lib": ["ESNext"],
     "moduleResolution": "Node",
     "noEmit": true,
+    "allowSyntheticDefaultImports": true,
     "noFallthroughCasesInSwitch": true,
     "noImplicitReturns": true,
     "noUnusedLocals": true,