[SPARK-30838] Add missing pages to documentation index

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Won't Fix
• Affects Version/s: 3.0.0
• Component/s: Documentation
• Assignee: Unassigned
• Reporter: Nicholas Chammas
• Created: 15/Feb/20 00:28
• Updated: 18/Feb/20 18:49
• Resolved: 18/Feb/20 18:49

Description

There are a few pages tracked in `docs/` that are not linked to from the top navigation or from the index page. Seems unintentional.

To make these pages easier to discover, we should at least list them in the index and link to them from other pages as appropriate.