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_001/sol2.py

@@ -0,0 +1,33 @@
+"""
+Problem Statement:
+If we list all the natural numbers below 10 that are multiples of 3 or 5,
+we get 3, 5, 6 and 9. The sum of these multiples is 23.
+Find the sum of all the multiples of 3 or 5 below N.
+"""
+
+
+def solution(n: int = 1000) -> int:
+    """Returns the sum of all the multiples of 3 or 5 below n.
+
+    >>> solution(3)
+    0
+    >>> solution(4)
+    3
+    >>> solution(10)
+    23
+    >>> solution(600)
+    83700
+    """
+
+    total = 0
+    terms = (n - 1) // 3
+    total += ((terms) * (6 + (terms - 1) * 3)) // 2  # total of an A.P.
+    terms = (n - 1) // 5
+    total += ((terms) * (10 + (terms - 1) * 5)) // 2
+    terms = (n - 1) // 15
+    total -= ((terms) * (30 + (terms - 1) * 15)) // 2
+    return total
+
+
+if __name__ == "__main__":
+    print(solution(int(input().strip())))