Reformat Cluster API Reference Documentation

[jrodewig]

Updates the cluster API documentation to match the Elastic API reference template.

Relates to elastic/docs#937 and #45195

• Cluster Health ([DOCS] Reformats cluster health and cluster state APIs #45206)
• Cluster State ([DOCS] Reformats cluster health and cluster state APIs #45206)
• Cluster Stats ( [DOCS] Reformats cluster stats API and expands common params #45270)
• Pending cluster tasks ([DOCS] Reformats cluster pending tasks API #45280)
• Cluster Reroute ([DOCS] Reformats cluster reroute API #45328)
• Cluster Update Settings ([DOCS] Reformats cluster update settings API #45337)
• Cluster Get Settings ([DOCS] Reformats cluster update settings API #45337)
• Nodes Stats ([DOCS] Reformats cluster node stats API #45441)
• Nodes Info ([DOCS] Reformats cluster node info API #45446)
• Nodes Feature Usage ([DOCS] Reformats nodes feature usage API #45539)
• Remote Cluster Info ([DOCS] Reformats cluster remote info API #45545)
• Task Management API ([DOCS] Reformats task management API #45549)
• Nodes hot_threads ([DOCS] Reformats nodes hot_threads API #45597)
• Cluster Allocation Explain API ([DOCS] Reformats cluster allocation explain API #45603)
• Voting Configuration Exclusions ([DOCS] Reformats voting configuration exclusion API #45644)

[elasticmachine]

Pinging @elastic/es-docs

[szabosteve]

Cluster API documentation has been updated. I close the issue.