Allowing `_doc` as a type will enable users to make the transition to 7.0
smoother since the index APIs will be `PUT index/_doc/id` and `POST index/_doc`.
This also moves most of the documentation to `_doc` as a type name.
Closes#27750Closes#27751
* Docs: Improved tokenizer docs
Added descriptions and runnable examples
* Addressed Nik's comments
* Added TESTRESPONSEs for all tokenizer examples
* Added TESTRESPONSEs for all analyzer examples too
* Added docs, examples, and TESTRESPONSES for character filters
* Skipping two tests:
One interprets "$1" as a stack variable - same problem exists with the REST tests
The other because the "took" value is always different
* Fixed tests with "took"
* Fixed failing tests and removed preserve_original from fingerprint analyzer
* Docs: First pass at improving analyzer docs
I've rewritten the intro to analyzers plus the docs
for all analyzers to provide working examples.
I've also removed:
* analyzer aliases (see #18244)
* analyzer versions (see #18267)
* snowball analyzer (see #8690)
Next steps will be tokenizers, token filters, char filters
* Fixed two typos