Add Data Structures - Aditya CSE (#6568)

* Add Data Structures - Aditya CSE

Creative Commons by/sa 3.0 (license on last page)

check_urls=http://adityacse.weebly.com/uploads/2/4/0/7/24078687/data-structures.pdf

* Correct URL to HTTPS

books/free-programming-books-subjects.md

@@ -96,6 +96,7 @@ Books that cover a specific programming language can be found in the  [BY PROGRA
 * [Animated Algorithm and Data Structure Visualization](http://visualgo.net) (Resource)
 * [Annotated Algorithms in Python: Applications in Physics, Biology, and Finance](https://github.com/mdipierro/nlib) - Massimo di Pierro
 * [Binary Trees](http://cslibrary.stanford.edu/110/BinaryTrees.pdf) (PDF)
+* [Data Structures](https://adityacse.weebly.com/uploads/2/4/0/7/24078687/data-structures.pdf) - Aditya CSE (PDF)
 * [Data Structures](https://en.wikibooks.org/wiki/Data_Structures) - Wikibooks
 * [Data Structures](http://www.cse.iitd.ernet.in/~suban/cs130/index.html) - Prof. Subhashis Banerjee, IIT Delhi
 * [Data Structures (Into Java) - Paul N. Hilfinger](http://www-inst.eecs.berkeley.edu/~cs61b/fa14/book2/data-structures.pdf) (PDF)