feat: added basic string checker

backend/UserConfig.ts

@@ -11,6 +11,11 @@ const numChecker = (val: any) => {
 	catch (err) { return false; }
 }
 
+/**
+ * Returns a boolean if the provided value is a non-empty string
+ */
+const basicStringChecker = (val: any) => typeof val === 'string' && val.length > 0;
+
 /**
  * User-config property type checker functions
  */