added "id: false" to HABTM join table example

Based on the instructions further down in section 3.3.2.
Getting Started Guide: posts_controller -> PostsController [ci skip]
Getting Started Guide: post.rb -> Post
Merge pull request #12356 from francisgo/patch-3

Getting Started Guide: posts_controller -> PostsController [ci skip]
Merge pull request #12349 from odigity/master

added "id: false" to HABTM join table example [ci skip]
[ci skip] escape unintended url in docs
Merge pull request #12371 from cciollaro/master

[ci skip] escape unintended url in docs
Merge pull request #12373 from francisgo/patch-6

Getting Started Guide: post.rb -> Post [ci skip]
[ci skip] Update scaffold output and change some words.

Scaffold output: add jbuilder, update timestamp (edge guide!)

Add some file breadcrumb (comment) to help reader find files.

Improve readability by adding some command outputs.

Thanks for great help from @senny.
Merge pull request #12338 from JuanitoFatas/generator

[ci skip] Update scaffold output and change some words.
Adds template dependencies rake task from cache_digests gem.

This adds the rake tasks `cache_digests:dependencies` and `cache_digests:nested_dependencies` from `cache_digests` gem.
Merge pull request #12376 from tvdeyen/cache-digests-rake-tasks

Adds template dependencies rake task from cache_digests gem.
Add new line after create action on CommentsController code example
Merge pull request #12379 from francisgo/patch-7

Add new line after create action on CommentsController code example [ci skip]
Add `#any_of` query method to active_record

This method is inspired by [any_of from
mongoid](http://two.mongoid.org/docs/querying/criteria.html#any_of).

It is hooked on `WhereChain`, just like `#not`, and allows to compute an
`OR` like query that leverages AR's `#where` syntax:

    manual_removal = User.where(id: params[:users][:destroy_ids])
    users = User.where.any_of(manual_removal, "email like '%@example.com'", {banned: true}).destroy_all

It can be used anywhere `#where` is expected to work :

    manual_removal = User.where(id: params[:users][:destroy_ids])
    User.where.any_of(manual_removal, "email like '%@example.com'", {banned: true})
    @company.users.where.any_of(manual_removal, "email like '%@example.com'", {banned: true})
    User.where(offline: false).where.any_of( manual_removal, "email like '%@example.com'", {banned: true})

Its main purpose is to both :

* remove the need to write a sql string when we want an `OR`
* allow to write dynamic `OR` queries, which would be a pain with a string

There's also a negative version, `#none_of`. This will return all active
users :

    banned_users = User.where(banned: true)
    unconfirmed_users = User.where("confirmed_at IS NULL")
    active_users = User.where.none_of(banned_users, unconfirmed_users)