Improve binary search documentation and explanation.

[avneeshkumar31311-cyber]

Changes Made

Added a short, clear explanation of the basic idea behind binary search to impove readibility and understandin for Beginners.

[algorithms-keeper]

Closing this pull request as invalid

@avneeshkumar31311-cyber, this pull request is being closed as none of the checkboxes have been marked. It is important that you go through the checklist and mark the ones relevant to this pull request. Please read the Contributing guidelines.

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