Add visualization documentation section

[andynu]

Description

• Add new 4.visualization.md with overview, getting started, env vars, application sections, and tips
• Renumber development docs from 4 to 5
• Update index.md to include visualization in toctree

Not sure how deep to go on the actual content of the QC/Cluster data. Perhaps some further detail from a biologist's perspective would be helpful there. I think I've captured the general overview, and technical details related to running it. Perhaps in too much detail in one place (We could probably drop the static assets env var documentation, we unless you expect others to want to make permanent public deployments, and if you expect that I could write a whole section on how we did that).

What is the nature of your change?

• Bug fix (fixes an issue).
• Enhancement (adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• This change requires a documentation update.

Checklist

Please ensure that all boxes are checked before indicating that a pull request is ready for review.

• My code follows the conventions of this project.
• I have updated the pyproject.toml to reflect the change as designated by semantic versioning.
• I have checked linting and formatting with ruff check and ruff format.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have deleted all non-relevant text in this pull request template.

[mat10d]

Sounds good, I can add to this soon!

[andynu]

@mat10d Great context and guidance. Thank you!
I think to resolve this conflict we want your new numbering, but I'd like you to double check that please.

[mat10d]

Yes, the updated numbering is correct--my bad, didn't realize that led to a conflict!

[mat10d]

Would you like me to rebase or do you want to give it another look?

[mat10d]

Thanks for these, LGTM