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_002/sol2.py

@@ -0,0 +1,39 @@
+"""
+Problem:
+Each new term in the Fibonacci sequence is generated by adding the previous two
+terms. By starting with 1 and 2, the first 10 terms will be:
+
+    1,2,3,5,8,13,21,34,55,89,..
+
+By considering the terms in the Fibonacci sequence whose values do not exceed
+n, find the sum of the even-valued terms. e.g. for n=10, we have {2,8}, sum is
+10.
+"""
+
+
+def solution(n: int = 4000000) -> int:
+    """Returns the sum of all fibonacci sequence even elements that are lower
+    or equals to n.
+
+    >>> solution(10)
+    10
+    >>> solution(15)
+    10
+    >>> solution(2)
+    2
+    >>> solution(1)
+    0
+    >>> solution(34)
+    44
+    """
+    even_fibs = []
+    a, b = 0, 1
+    while b <= n:
+        if b % 2 == 0:
+            even_fibs.append(b)
+        a, b = b, a + b
+    return sum(even_fibs)
+
+
+if __name__ == "__main__":
+    print(solution(int(input().strip())))