[Maths]: Added `ThreeDivisors` problem.

[Akshit6828]

Pull Request Template

Added ThreeDivisors leetcode problem number 1952.

Note: The problem is based on a property of prime numbers.

Algo Facts:

• Check if the number is a square of a prime number and square of prime numbers ONLY have 3 divisors.
• Read the code submitted for a better understanding of the Algorithm.

Put check marks:

Have you made changes in README file ?

• [x] Added problem & solution under correct topic.
• [x] Specified Space & Time complexity.
• [x] Specified difficulty level, tag & Note(if any).

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Please also note any relevant details for your test configuration.

• [ ] Test A
• [ ] Test B

Make sure all below guidelines are followed else PR will get Reject:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code so that it is easy to understand
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] Any dependent changes have been merged and published in downstream modules

[welcome[bot]]

I can tell this is your first pull request! Thank you I'm so honored. :tada::tada::tada: I'll take a look at it ASAP!