DOC: Add data= examples and async note (fix #2809)

[OPMTerra]

This PR improves documentation for the data parameter in array creation (#2809).

What's Included

• Example using data=... for concise array creation
• Code comparison showing equivalent methods

Verification

✅ Docs updated in user-guide/arrays.rst
✅ Built & previewed locally ([screenshot]( ) ✅ No code changes needed

These changes help users:

1. Write cleaner, more readable code
2. Understand method equivalence

I'm happy to make any adjustments needed! 😊
@OPMTerra

[OPMTerra]

I've updated the screenshot to reflect the latest changes:

• Removed redundant shape parameter
• Simplified code example