feat: populate note files with problem descriptions and code stubs

Add populate-notes.mjs that fetches problem descriptions and
Python/C++ code stubs from LeetCode's GraphQL API. Populated
all 197 NeetCode 150 note files with:
- Problem description (examples, constraints)
- Python code stub (function signature)
- C++ code stub (function signature + includes)

API responses cached in leetcode/.cache/leetcode/ for instant re-runs.

org/study_deck_02/dsa/stack/1544-make-the-string-great.org

@@ -1,18 +1,75 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 1544. Make The String Great :easy:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*1544. Make The String Great][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*1544. Make The String Great][1544. Make The String Great]]
 :END:
 
+Given a string ~s~ of lower and upper case English letters.
+
+A good string is a string which doesn't have *two adjacent characters* ~s[i]~ and ~s[i + 1]~ where:
+
+ - ~0 <= i <= s.length - 2~
+
+ - ~s[i]~ is a lower-case letter and ~s[i + 1]~ is the same letter but in upper-case or *vice-versa*.
+
+To make the string good, you can choose *two adjacent* characters that make the string bad and remove them. You can keep doing this until the string becomes good.
+
+Return /the string/ after making it good. The answer is guaranteed to be unique under the given constraints.
+
+*Notice* that an empty string is also good.
+
+*Example 1:*
+
+
+#+begin_src
+Input: s = "leEeetcode"
+Output: "leetcode"
+Explanation: In the first step, either you choose i = 1 or i = 2, both will result "leEeetcode" to be reduced to "leetcode".
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: s = "abBAcC"
+Output: ""
+Explanation: We have many possible scenarios, and all lead to the same answer. For example:
+"abBAcC" --> "aAcC" --> "cC" --> ""
+"abBAcC" --> "abBA" --> "aA" --> ""
+#+end_src
+
+
+*Example 3:*
+
+
+#+begin_src
+Input: s = "s"
+Output: "s"
+#+end_src
+
+
+*Constraints:*
+
+ - ~1 <= s.length <= 100~
+
+ - ~s~ contains only lower and upper case English letters.
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def makeGood(self, s: str) -> str:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    string makeGood(string s) {
+        
+    }
+};
 #+end_src