fix: Json column migration generation (#339)

Co-authored-by: Nicola Marcacci Rossi <nicola@smartive.ch>

Author: nickredmark

src/migrations/generate.ts

@@ -677,7 +677,7 @@ export class MigrationGenerator {
         col();
         break;
       case 'json':
-        this.writer.writeLine(`table.json('${typeToField(name)}');`);
+        col(`table.json('${typeToField(name)}')`);
         break;
       case 'custom':
         throw new Error(`Can't create a column for ${name} because it's a custom field`);