Add Fixed Point Iteration and Modified Newton-Raphson Methods

[akshat3144]

Describe your change:

This pull request adds two numerical analysis algorithms:

Fixed Point Iteration Method: An iterative method to find an approximate solution to the equation ( f(x) = 0 ) by rewriting it in the form ( x = g(x) ). Includes implementation with docstrings, type hints, and doctests.

Modified Newton-Raphson Method: An iterative method that modifies the standard Newton-Raphson method to improve convergence when the root has multiplicity greater than one. Includes implementation with docstrings, type hints, and doctests.

Both algorithms are placed in the appropriate directory with filenames in lowercase without spaces or dashes.

• [X] Add an algorithm?
• [ ] Fix a bug or typo in an existing algorithm?
• [ ] Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• [ ] Documentation change?

Checklist:

• [X] I have read CONTRIBUTING.md.
• [X] This pull request is all my own work -- I have not plagiarized.
• [X] I know that pull requests will not be merged if they fail the automated tests.
• [ ] This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• [X] All new Python files are placed inside an existing directory.
• [X] All filenames are in all lowercase characters with no spaces or dashes.
• [X] All functions and variable names follow Python naming conventions.
• [X] All function parameters and return values are annotated with Python type hints.
• [X] All functions have doctests that pass the automated testing.
• [X] All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• [X] If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".