Let schema/config.json end with a line feed

Some editors add one automatically when saving the file, which causes confusion
and ugly diffs containing `\ No newline at end of file`.

pkg/jsonschema/generate.go

@@ -20,6 +20,7 @@ func GetSchemaDir() string {
 func GenerateSchema() {
 	schema := customReflect(&config.UserConfig{})
 	obj, _ := json.MarshalIndent(schema, "", "  ")
+	obj = append(obj, '\n')
 
 	if err := os.WriteFile(GetSchemaDir()+"/config.json", obj, 0o644); err != nil {
 		fmt.Println("Error writing to file:", err)

schema/config.json

@@ -1725,4 +1725,4 @@
   },
   "additionalProperties": false,
   "type": "object"
-}
+}