Remove surplus period from assertion messages
[ci skip] Improve doc, fix grammatical issue
[ci skip] Use plain underscore instead of "\_".
Write the failing test case for concurrent counter cache
Make counter cache decrementation on destroy idempotent
Merge pull request #14732 from JuanitoFatas/doc/patch1

[ci skip] Use plain underscore instead of "\_". [ci skip]
Disable assest cache store in docs [ci skip]
Merge pull request #14737 from nickborromeo/disable-asset-cache-docs

Disable assest cache store in docs [ci skip]
read_attribute is public, so we should just call it
again, read_attribute is public, so just call it
- Fix lingering reference to `:text` instead of the newer `:plain`
- Section references `form_tag` instead of the `form_for` used in the example
Just call read_attribute, no need to use `send`.

Follow up to af549a1ad6692d7e2c756750651f0e1b293f5185
Merge pull request #14740 from laurocaetano/read-attribute

Just call read_attribute, no need to use send.
Merge pull request #14739 from oysta/guide-fixes

Fix some inconsistent references between text and example code in getting started guide [ci skip]
docs, double meaning of `serialize` argument. Closes #14284.

The second argument to serialize has double meaning:
  * `class_name` of the Type to serialize
  * `coder` to use then serializing.

The new variable name and the docs better describe that behavior.
Display diagnostics in text format for xhr request
`collection_check_boxes` respects `:index` option for the hidden filed name.

closes #14147
Merge pull request #14736 from nashby/hidden-index

`collection_check_boxes` respects `:index` option for the hidden filed name
Use the index on hidden field
[ci skip] Added link to ruby-lang.org installation.