`skiping` => `skipping`
Fixed typos in shallow routes and routing concerns

Grammatical tense correction: "There exists two" => "There exist two".
Plurality correction: "can be reused inside others resources" => "can be reused inside other resources".
Merge pull request #12942 from kuldeepaggarwal/typos

`skiping` => `skipping` [ci skip]
Merge pull request #12945 from fluxusfrequency/patch-1

Fixed typos in "shallow routes" and "routing concerns" in routing.md [ci skip]
[ci skip] `apropriate` => `appropriate`, spaces added
Merge pull request #12949 from akshay-vishnoi/documentation

[ci skip] `apropriate` => `appropriate`, spaces added
use `4-0-stable` arel branch to get bundle working again.

this resolves the following error when running `bundle install`

```
ArgumentError: wrong number of arguments (2 for 1)
    /Users/senny/Projects/rails/.bundle/bundler/gems/arel-454a25f18c95/lib/arel/crud.rb:5:in `compile_update'
```

The build is still broken with lots of:

```
ArgumentError: wrong number of arguments (2 for 1)
    /Users/senny/Projects/rails/.bundle/bundler/gems/arel-454a25f18c95/lib/arel/crud.rb:5:in `compile_update'
```
use arel `master` and update activerecord to depend on arel `5.0.0`.

This is a follow-up to 3053fee954c1e28b23f7e00921d7b9b3b3867fa5.

> The `master` branch should use the `master` branch.
Revert "Explicitly exit with status "1" for create and drop failures"

This reverts commit 22f80ae57b26907f662b7fd50a7270a6381e527e.

See
https://github.com/rails/rails/commit/22f80ae57b26907f662b7fd50a7270a6381e527e#commitcomment-4640676

Conflicts:
	activerecord/CHANGELOG.md
Revert "Properly require database tasks so we have access to the raised constant"

This reverts commit fbcd46b1a0d255a34d29caa77bbd31c287446333.

This is not needed anymore. See 7280965
use arel nodes to represent non-string `order_values`.

This fixes a bug when merging relations of different classes.

```
Given:
  Post.joins(:author).merge(Author.order(name: :desc)).to_sql

Before:
 SELECT "posts".* FROM "posts"
   INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
   ORDER BY "posts"."name" DESC

After:
 SELECT "posts".* FROM "posts"
   INNER JOIN "authors" ON "authors"."id" = "posts"."author_id"
   ORDER BY "authors"."name" DESC
```