Add Line search Docs

[antoinebou12]

This pull request focuses on improving the documentation for solvers and tutorials. The changes include grammatical corrections, additional explanations, and detailed descriptions of optimization techniques.

Documentation improvements:

• docs/details/solvers.md: Corrected grammatical errors and improved the readability of the linear solver options section.
• docs/details/solvers.md: Enhanced the explanation of the gradient norm and update direction norm for convergence checks, providing clearer benefits and usage notes.
• docs/details/solvers.md: Added detailed descriptions and parameters for line search, backtracking line search, and robust Armijo methods, including mathematical formulations and references.

Tutorial corrections:

• docs/tutorials/sling-shot/sling-shot.md: Fixed the GitHub link for the Slingshot Tutorial repository to ensure accurate referencing.