docs: Add ASF attribution

[simicd]

Which issue does this PR close?

Closes #950

Rationale for this change

Aligning Apache Software Foundation attribution across projects

What changes are included in this PR?

• Add ASF footer
• Update docs requirements.txt (align with arrow-datafusion)
• Fix issues preventing docs compilation

Are there any user-facing changes?

Updated footer on documentation website

[simicd]

Thanks for your feedback @andygrove! Made the updates and all checks are passing