Reformat cat API Reference Documentation

[jrodewig]

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

Relates to elastic/docs#937 and #45195

• cat aliases ([DOCS] Reformat cat alias API  #45119)
• cat allocation ([DOCS] Reformats cat allocation API #45158)
• cat count ([DOCS] Reformat cat count API #45160)
• cat fielddata ([DOCS] Reformat cat fielddata API #45202)
• cat health ([DOCS] Reformat cat health API #45218)
• cat indices ([DOCS] Reformat cat indices API #45239)
• cat master ([DOCS] Reformat cat master API #45240)
• cat nodeattrs ([DOCS] Reformats cat nodeattrs API #45255)
• cat nodes ([DOCS] Reformats cat nodes API #45285)
• cat pending tasks ([DOCS] Reformats cat pending tasks API #45287)
• cat plugins ([DOCS] Reformats cat plugins API #45344)
• cat recovery ([DOCS] Reformats cat recovery API #45345)
• cat repositories ([DOCS] Reformats cat repositories API #45382)
• cat thread pool ([DOCS] Reformats cat thread pool API #45385)
• cat shards ([DOCS] Reformats cat shards API #45392)
• cat segments ([DOCS] Reformats cat segments API #45397)
• cat snapshots ([DOCS] Reformats cat snapshots API #45402)
• cat templates ([DOCS] Reformats cat templates API #45403)

[elasticmachine]

Pinging @elastic/es-docs