docs: Fix reST formatting in ARModel methods

[sohampatil01-svg]

Describe your changes

Fixes strict reStructuredText (reST) formatting errors (unexpected unindents and missing blank lines) in ARModel methods. This ensures the documentation builds correctly in Sphinx.

Issue Link

Fixes #442

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
• 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.

[alphaleporus]

Hi @sohampatil01-svg, thanks for looking into this! I noticed this duplicates the PR I opened yesterday (#442) based on @sadamov's direct feedback from my earlier Sphinx introspection POC.

Looking at your diff, it appears this PR only updates the common_step docstring. Just a heads up: when I ran the Sphinx build locally, it also threw unexpected unindent errors for plot_examples and aggregate_and_plot_metrics. My PR (#442) covers all three to ensure the build passes cleanly.

I also see you added a CHANGELOG entry here. Great catch! I intentionally left the CHANGELOG update for the maintainers to flag during review (per the 'Author checklist after completed review' section of the PR template), but I'm happy to pull that into #442 if the maintainers prefer.

Since #442 already contains the complete fix for all three methods, I'll defer to @sadamov or @joeloskarsson on how they'd like to proceed!

[sadamov]

closeing as duplicate of #442