✨ feat(eular_11.py)：添加欧拉项目第11题的解决方案，使用NumPy计算网格中四个相邻数字的最大乘积

✨ feat(eular_12.py)：添加欧拉项目第12题的解决方案，计算第一个拥有超过500个因数的三角数
📝 docs(readme.md)：添加三角数的详细文档，涵盖数学概念、应用领域和博弈论中的实际例子

solutions/0012.TriangularNumber/eular_12.py

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+"""
+The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number
+would be 1+2+3+4+5+6+7=28. The first ten terms would be:
+
+    1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...
+
+Let us list the factors of the first seven triangle numbers:
+
+1 : 1
+3 : 1, 3
+6 : 1, 2, 3, 6
+10 : 1, 2, 5, 10
+15 : 1, 3, 5, 15
+21 : 1, 3, 7, 21
+28 : 1, 2, 4, 7, 14, 28
+
+We can see that 28 is the first triangle number to have over five divisors.
+What is the value of the first triangle number to have over five hundred divisors?
+
+NOTE：
+
+-> in Math
+    解法的核心是找到所有质因数及对应的最大幂, 根据组合数学的方法估算因数数量
+-> in Coding
+    循环遍历
+"""
+
+import math
+import time
+
+
+def timer(func):
+    def wrapper(*args, **kwargs):
+        start_time = time.time()
+        result = func(*args, **kwargs)
+        end_time = time.time()
+        print(f"Time taken: {end_time - start_time} seconds")
+        return result
+
+    return wrapper
+
+
+def get_factors(n):
+    if n == 0:
+        raise ValueError("0 没有因数集合")
+    n = abs(n)  # 处理负数
+    factors = set()
+    for i in range(1, int(math.isqrt(n)) + 1):
+        if n % i == 0:
+            factors.add(i)
+            factors.add(n // i)
+    return sorted(factors)
+
+
+def get_triangle_number(n: int) -> int:
+    return n * (n + 1) // 2
+
+
+@timer
+def main_coding() -> None:
+    n = 1
+    while True:
+        triangle_number = get_triangle_number(n)
+        factors = get_factors(triangle_number)
+        if len(factors) > 500:
+            print(triangle_number)
+            break
+        n += 1
+
+
+if __name__ == "__main__":
+    main_coding()