docs: Update doc about CSV upload

[seiyab]

SUMMARY

Docs about CSV upload is stale. I update it to match current UI.

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

NOTE: not full difference.
Before:

After:

TESTING INSTRUCTIONS

N/A. Just updating doc.

ADDITIONAL INFORMATION

• Has associated issue: HOW TO ENABLE CSV FILE UPLOAD ,showing ERROR: No database is allowed for your csv upload #14143
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[github-actions]

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[rusackas]

LGTM! Thank you for the help here!

And congrats on the first commit. Feel free to add your org to the In the Wild Page, too!

[seiyab]

Thank you for your review.
Our organization has not decided to use Superset yet. I will add it when I will contribute Superset again after our org stating to use it. Thanks.