Add default value to each one of the usages of `allow_no_indices`
since it differs between different APIs.
Relates to: #52534
(cherry picked from commit 2eb986488ac326d6da6ab8ad0203a94e08684a36)
Several files in the REST APIs nav section are included using
:leveloffset: tags. This increments headings (h2 -> h3, h3 -> h4, etc.)
in those files and removes the :leveloffset: tags.
Other supporting changes:
* Alphabetizes top-level REST API nav items.
* Change 'indices APIs' heading to 'index APIs.'
* Changes 'Snapshot lifecycle management' heading to sentence case.
* Removed the docs for `index.compound_format` and `index.compound_on_flush` - these are expert settings which should probably be removed (see https://github.com/elastic/elasticsearch/issues/10778)
* Removed the docs for `index.index_concurrency` - another expert setting
* Labelled the segments verbose output as experimental
* Marked the `compression`, `precision_threshold` and `rehash` options as experimental in the cardinality and percentile aggs
* Improved the experimental text on `significant_terms`, `execution_hint` in the terms agg, and `terminate_after` param on count and search
* Removed the experimental flag on the `geobounds` agg
* Marked the settings in the `merge` and `store` modules as experimental, rather than the modules themselves
Closes#10782
additional element per segment.
This commit adds a verbose flag to the _segments api. Currently the
only additional information returned when set to true is the full
ram tree from lucene for each segment.