Add some important questions of DSA in C language.

[RaaggeeS]

I would like to add a folder of DSA, which would consist of some unique questions.
Topics would be:

1. Doubly Linked List
2. Binary Search
3. Shell Sort
4. Queue Class

Please review it under Hacktoberfest.

[Ulton321]

DSA/
│
├── Doubly_Linked_List/
│ ├── question_1.py
│ ├── question_2.py
│ └── README.md
│
├── Binary_Search/
│ ├── question_1.py
│ ├── question_2.py
│ └── README.md
│
├── Shell_Sort/
│ ├── question_1.py
│ ├── question_2.py
│ └── README.md
│
└── Queue_Class/
├── question_1.py
├── question_2.py
└── README.md