Add template docs

[rdettai]

Description

Closes #4480

How was this PR tested?

Navigating the swagger UI

[rdettai]

FYI @Mo3m3n

[rdettai]

TODO: just noticed the auto_create_indexes also needs to be documented

EDIT: It is actually enabled by default (and hardcoded)

quickwit/quickwit/quickwit-serve/src/lib.rs

Lines 1059 to 1065 in fc5bdab

	let cluster_config = ClusterConfig {
	cluster_id,
	auto_create_indexes: true,
	default_index_root_uri,
	replication_factor,
	shard_throughput_limit: ingest_api_config.shard_throughput_limit,
	};

[guilload]

Looking good, but can we use index template instead of simply template in the wording?

[guilload]

Suggested change

	title: Template configuration
	title: Index template configuration

[guilload]

Suggested change

	This page describes how to configure a template.
	This page describes how to configure an index template.

[guilload]

Suggested change

	Templates let you dynamically create indexes according to predefined rules. Templates are used automatically when documents are received on the ingest API for an index that doesn't exist.
	Index templates let you dynamically create indexes according to predefined rules. Templates are used automatically when documents are received on the ingest API for an index that doesn't exist.