Altered Sub-Directories -- Added New Solutions

1. Solutions archive subdirectories model changed
2. Solutions added:
a. Python-Bank_Queue_Sim
b. Python-Binary_Search_Tree
c. Python-Derangements_Memoization
d. Python-Derangements_Recursive
e. Python-Nesting_Level
f. Python-Stair_Count
g. Python-Towers_of_Hanoi_Iterative
h. Python-Towers_of_Hanoi_Recursive
i. Python-Tree_Max_Val