Adding Pi calculation algorithms for Pi Day

[aidnyu]

This PR introduces two Pi calculation implementations with doc tests:

• Adding Chudnovsky algorithm implementation (chudnovsky_algorithm.mojo)
• Adding Leibniz formula for Pi calculation (leibniz_pi_formula.mojo)

• I have performed a self-review of my code
• My code follows the style guidelines of this project
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Comments in areas I changed are up to date
• I have added comments to hard-to-understand areas of my code

[aidnyu]

Hi @SatinWukerORIG,

I've also submitted a separate PR to update the current Mojo version(#13). Since that PR includes important version updates that this work builds upon, it would be helpful if you could review and merge that one first.

Thank you!