This further applies the pattern set in #34125 to reduce copy-and-paste
in the single document CRUD portion of the High Level REST Client docs.
It also adds line wraps to snippets that are too wide to fit into the box
when rendered in the docs, following up on the work started in #34163.
Some features have been deprecated since `6.0` like the `_parent` field or the
ability to have multiple types per index. This allows to remove quite some
code, which in-turn will hopefully make it easier to proceed with the removal
of types.
The REST Client is split into 2 parts:
* Low level
* High level
The High level client has a main common section and the document delete API documentation as a start.
Nik Everett
Adrien Grand
Luca Cavanna
David Pilato