feat(curriculum): add grouping characters challenge and guide (#34875)

Added new challenge for mixed grouping of characters

guide/english/certifications/javascript-algorithms-and-data-structures/regular-expressions/check-for-mixed-grouping-of-characters/index.md

@@ -0,0 +1,24 @@
+---
+title: Check For Mixed Grouping of Characters
+---
+## Check For Mixed Grouping of Characters
+
+### Hint 1
+
+Use `a|b` to check for either `a` or `b`.
+
+### Hint 2
+
+Your regex should use mixed grouping like `/P(engu|umpk)in/g`.
+
+### Hint 3
+
+Use `.*` to allow for middle names.
+
+### Solution
+
+```javascript
+let myString = "Eleanor Roosevelt";
+let myRegex = /(Franklin|Eleanor).*Roosevelt/;
+let result = myRegex.test(myString);
+```