feat(ga, api): Implement advanced GA strategy and refactor API for v0.4.0 (#16)

This commit introduces a major enhancement to the genetic algorithm's convergence logic and refactors key parts of the API for better clarity and usability.

- **feat(ga):** Re-implements the GA solver (CPU & CUDA) to use a more robust strategy based on Elitism, Crossover, and Mutation. This replaces the previous, less efficient model and is designed to significantly improve accuracy and convergence speed.

- **feat(api):** Updates `GA_Options` to expose the new GA strategy parameters:
    - Renames `mutation_percentage` to `mutation_strength` for clarity.
    - Adds `elite_ratio`, `crossover_ratio`, and `mutation_ratio`.
    - Includes a `__post_init__` validator to ensure ratios are valid.

- **refactor(api):** Moves `quadratic_solve` from a standalone function to a method of the `Function` class (`f1.quadratic_solve()`). This provides a cleaner, more object-oriented API.

- **docs:** Updates the README, `GA_Options` doc page, and `quadratic_solve` doc page to reflect all API changes, new parameters, and updated usage examples.

- **chore:** Bumps version to 0.4.0.

Reviewed-on: #16
Co-authored-by: Jonathan Rampersad <rampersad.jonathan@gmail.com>
Co-committed-by: Jonathan Rampersad <rampersad.jonathan@gmail.com>

pyproject.toml

@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 # --- Core Metadata ---
 name = "polysolve"
-version = "0.3.2"
+version = "0.4.0"
 authors = [
   { name="Jonathan Rampersad", email="jonathan@jono-rams.work" },
 ]