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_053/sol1.py

@@ -0,0 +1,43 @@
+"""
+Combinatoric selections
+Problem 53
+
+There are exactly ten ways of selecting three from five, 12345:
+
+    123, 124, 125, 134, 135, 145, 234, 235, 245, and 345
+
+In combinatorics, we use the notation, 5C3 = 10.
+
+In general,
+
+nCr = n!/(r!(n−r)!),where r ≤ n, n! = n×(n−1)×...×3×2×1, and 0! = 1.
+It is not until n = 23, that a value exceeds one-million: 23C10 = 1144066.
+
+How many, not necessarily distinct, values of nCr, for 1 ≤ n ≤ 100, are greater
+than one-million?
+"""
+from math import factorial
+
+
+def combinations(n, r):
+    return factorial(n) / (factorial(r) * factorial(n - r))
+
+
+def solution():
+    """Returns the number of values of nCr, for 1 ≤ n ≤ 100, are greater than
+    one-million
+
+    >>> solution()
+    4075
+    """
+    total = 0
+
+    for i in range(1, 101):
+        for j in range(1, i + 1):
+            if combinations(i, j) > 1e6:
+                total += 1
+    return total
+
+
+if __name__ == "__main__":
+    print(solution())