Add Sphinx-based documentation system and supporting files.

[Lakshya-2440]

Describe your changes

Added a complete Sphinx-based documentation system under docs/ with .rst files, Makefile, conf.py, and supporting scripts.
Included CONTRIBUTING.md and DOCUMENTATION_SETUP.md for contributor and documentation setup guidance.
Added scripts for documentation and example runs.

Issue Link

closes #61

Type of change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📖 Documentation (Addition or improvements to documentation)

Checklist before requesting a review

• My branch is up-to-date with the target branch - if not update your fork with the changes from the target branch (use pull with --rebase option if possible).
• I have performed a self-review of my code
• For any new/modified functions/classes I have added docstrings that clearly describe its purpose, expected inputs and returned values
• I have placed in-line comments to clarify the intent of any hard-to-understand passages of my code
• I have updated the README to cover introduced code changes
• I have added tests that prove my fix is effective or that my feature works
• I have given the PR a name that clearly describes the change, written in imperative form (context).
• I have requested a reviewer and an assignee (assignee is responsible for merging). This applies only if you have write access to the repo, otherwise feel free to tag a maintainer to add a reviewer and assignee.

Checklist for reviewers

Each PR comes with its own improvements and flaws. The reviewer should check the following:

• the code is readable
• the code is well tested
• the code is documented (including return types and parameters)
• the code is easy to maintain

Author checklist after completed review

• I have added a line to the CHANGELOG describing this change, in a section
  reflecting type of change (add section where missing):
  • added: when you have added new functionality
  • changed: when default behaviour of the code has been changed
  • fixes: when your contribution fixes a bug
  • maintenance: when your contribution is relates to repo maintenance, e.g. CI/CD or documentation

Checklist for assignee

• PR is up to date with the base branch
• the tests pass
• (if the PR is not just maintenance/bugfix) the PR is assigned to the next milestone. If it is not, propose it for a future milestone.
• author has added an entry to the changelog (and designated the change as added, changed, fixed or maintenance)
• Once the PR is ready to be merged, squash commits and merge the PR.

[sadamov]

closing as duplicate of #272 and #252

[Lakshya-2440]

@sadamov neither of those PRs are completely correct or even completed, my PR is completed, have deployed a good documentation system

[sadamov]

@Lakshya-2440 i understand, could you bring up this topic at the next dev meeting? So far we tried to keep open only 2 prs to maintain some sense of structure (one docstrings, one autodocs). No duplicate PRs has been a core principle for us during GSoC so far. But several people have opened separate PRs on autodoc and I think the dev meeting would be the best place to align ourselves.