Document error bars behavior in ag3.plot_frequencies_time_series

[adilraza99]

Fixes #826

This PR adds documentation to the plot_frequencies_time_series function to clarify what the displayed error bars represent.

Changes

• Updated the docstring returns section in malariagen_data/anoph/frq_base.py
• Documented that error bars represent 95% confidence intervals
• Specified Wilson score method usage via statsmodels.stats.proportion.proportion_confint()
• Clarified asymmetric upper/lower bounds behavior

Verification

• Documentation-only change (no logic modified)
• No imports or dependencies changed
• Clean single commit
• Formatting and line length compliant
• Safe for CI validation

[adilraza99]

Hi maintainers,

This PR only updates documentation and does not modify any application logic or dependencies.
Please let me know if you'd like anything adjusted or clarified.

Thanks!

[adilraza99]

@jonbrenas could you please take a look at this PR? The documentation updates address the issue and have been verified on my side. Just want to confirm everything looks good from your perspective.

[jonbrenas]

LGTM

[jonbrenas]

Thanks, @adilraza99. This is perfect!

[adilraza99]

@jonbrenas Thanks a lot, I’m really glad the changes were helpful! I enjoyed working on this PR and would love to keep contributing to the project.

I’m also exploring potential GSoC organizations this year and was looking into Sanger Tree of Life. I didn’t see this repository listed there, so I wanted to ask whether continuing to contribute here would be a good way to get more involved with the project overall.