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/greedy/0846-hand-of-straights.org

@@ -1,18 +1,58 @@
 #+PROPERTY: STUDY_DECK_02
 * TODO 0846. Hand of Straights :medium:
 :PROPERTIES:
-:NEETCODE: [[file:../../roadmap.org::*0846. Hand of Straights][Roadmap]]
+:NEETCODE: [[file:../../roadmap.org::*0846. Hand of Straights][0846. Hand of Straights]]
 :END:
 
+Alice has some number of cards and she wants to rearrange the cards into groups so that each group is of size ~groupSize~, and consists of ~groupSize~ consecutive cards.
+
+Given an integer array ~hand~ where ~hand[i]~ is the value written on the ~i^{th}~ card and an integer ~groupSize~, return ~true~ if she can rearrange the cards, or ~false~ otherwise.
+
+*Example 1:*
+
+
+#+begin_src
+Input: hand = [1,2,3,6,2,3,4,7,8], groupSize = 3
+Output: true
+Explanation: Alice's hand can be rearranged as [1,2,3],[2,3,4],[6,7,8]
+#+end_src
+
+
+*Example 2:*
+
+
+#+begin_src
+Input: hand = [1,2,3,4,5], groupSize = 4
+Output: false
+Explanation: Alice's hand can not be rearranged into groups of 4.
+#+end_src
+
+
+*Constraints:*
+
+ - ~1 <= hand.length <= 10^{4}~
+
+ - ~0 <= hand[i] <= 10^{9}~
+
+ - ~1 <= groupSize <= hand.length~
+
+*Note:* This question is the same as 1296: https://leetcode.com/problems/divide-array-in-sets-of-k-consecutive-numbers/
+
 ** TODO Approach
 Write your approach here.
 
 ** TODO Python
 #+begin_src python
-
+class Solution:
+    def isNStraightHand(self, hand: List[int], groupSize: int) -> bool:
 #+end_src
 
 ** TODO C++
 #+begin_src cpp
-
+class Solution {
+public:
+    bool isNStraightHand(vector<int>& hand, int groupSize) {
+        
+    }
+};
 #+end_src