Rename Project Euler directories and other dependent changes (#3300)

* Rename all Project Euler directories:

Reason:
The change was done to maintain consistency throughout the directory
and to keep all directories in sorted order.

Due to the above change, some config files had to be modified:
'problem_22` -> `problem_022`

* Update scripts to pad zeroes in PE directories

project_euler/problem_020/sol1.py

@@ -0,0 +1,54 @@
+"""
+Problem 20: https://projecteuler.net/problem=20
+
+n! means n × (n − 1) × ... × 3 × 2 × 1
+
+For example, 10! = 10 × 9 × ... × 3 × 2 × 1 = 3628800,
+and the sum of the digits in the number 10! is 3 + 6 + 2 + 8 + 8 + 0 + 0 = 27.
+
+Find the sum of the digits in the number 100!
+"""
+
+
+def factorial(num: int) -> int:
+    """Find the factorial of a given number n"""
+    fact = 1
+    for i in range(1, num + 1):
+        fact *= i
+    return fact
+
+
+def split_and_add(number: int) -> int:
+    """Split number digits and add them."""
+    sum_of_digits = 0
+    while number > 0:
+        last_digit = number % 10
+        sum_of_digits += last_digit
+        number = number // 10  # Removing the last_digit from the given number
+    return sum_of_digits
+
+
+def solution(num: int = 100) -> int:
+    """Returns the sum of the digits in the factorial of num
+    >>> solution(100)
+    648
+    >>> solution(50)
+    216
+    >>> solution(10)
+    27
+    >>> solution(5)
+    3
+    >>> solution(3)
+    6
+    >>> solution(2)
+    2
+    >>> solution(1)
+    1
+    """
+    nfact = factorial(num)
+    result = split_and_add(nfact)
+    return result
+
+
+if __name__ == "__main__":
+    print(solution(int(input("Enter the Number: ").strip())))