fix: add additional tests for Regular Expression challenge (#18696)

fix(curriculum): add additional tests and solution for Restrict Possible Usernames challenge

curriculum/challenges/english/02-javascript-algorithms-and-data-structures/regular-expressions/restrict-possible-usernames.english.md

@@ -35,6 +35,10 @@ tests:
     testString: assert(!userCheck.test("007"), 'Your regex should not match <code>007</code>');
   - text: Your regex should not match <code>9</code>
     testString: assert(!userCheck.test("9"), 'Your regex should not match <code>9</code>');
+  - text: Your regex should not match <code>A1</code>
+    testString: assert(!userCheck.test("A1"), 'Your regex should not match <code>A1</code>');
+  - text: Your regex should not match <code>BadUs3rnam3</code>
+    testString: assert(!userCheck.test("BadUs3rnam3"), 'Your regex should not match <code>BadUs3rnam3</code>');
 
 ```
 
@@ -61,6 +65,7 @@ let result = userCheck.test(username);
 <section id='solution'>
 
 ```js
-// solution required
+const userCheck = /^[A-Za-z]{2,}\d*$/;
 ```
+
 </section>