segment trees questions added

[Manish2397]

Segment trees tutorial with question added.

[papachristoumarios]

Hello @Manish2397,

This seems to be code for segment trees. Your PR is labeled as questions for segment trees.
Also consider formatting your code well and adding testcases to it.

[mstou]

Hello @Manish2397 , thanks for contributing. Can you please move the Segment tree folder to Data Structures/ Advanced DS/ Segment Trees instead of the root folder so as to follow the structure described in README?

We would also like you to provide a more thorough documentation of the code, as also indicated by @papachristoumarios.

Lastly, instead of implementing 2 segment trees (one for min/max querries and one for range sum querries) you could implement 1 generic segment tree that works with a function f (int f(int x, int y)). In the first case f would be int f(int x, int y){ return min(x,y); } and in the range sum segment tree it would be: int f(int x, int y){ return x+y; }

[mstou]

For example, in the generic segment tree described in my comment, line 22 would be:
tree[index] = f( tree[2*index], tree[2*index+1] );