Add real world applications of important algorithms and problem statements in md files

[satyamgupta11692]

As a developer, I would also like to know the real world application of problem statements and algorithms to understand and learn them easily from the leetcode-solutions markdown files.

For example: Following information could be added for https://github.com/AlgoMaster-io/leetcode-solutions/blob/main/java/majority-element.md problem statement:

1. Voting Algorithm : Determining the winner of an election based on majority rule, where the candidate with more than half the votes wins.