Some general grammar and style fixes in the book
Merge remote-tracking branch 'upstream/2.3' into general-grammar-and-style-fixes

Conflicts:
	book/forms.rst
Fixes incorrect latin abbrev
Some more fixes after proofreading
add validation config reference section
use a global Composer installation
Fix typo: than in Twig => than Twig templates

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3
| Fixed tickets | #4696
[Cookbook] Fix XML example of RTE
minor #4679 General grammar and style fixes in the book (frne)

This PR was merged into the 2.3 branch.

Discussion
----------

General grammar and style fixes in the book

Contains numerous grammar, style and readability fixes (see diff)

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | >= 2.3
| Fixed tickets |

Commits
-------

86d7a6d Some more fixes after proofreading
5c754e0 Fixes incorrect latin abbrev
7e4904f Merge remote-tracking branch 'upstream/2.3' into general-grammar-and-style-fixes
1da061c Some general grammar and style fixes in the book
minor #4706 Fix typo: than in Twig => than Twig templates (ifdattic)

This PR was merged into the 2.3 branch.

Discussion
----------

Fix typo: than in Twig => than Twig templates

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3
| Fixed tickets | #4696

Commits
-------

a8ec695 Fix typo: than in Twig => than Twig templates
feature #4173 use a global Composer installation (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

use a global Composer installation

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | #4170

This pull request replaces all mentions of local Composer installations, but uses a gobal Composer installation instead.

**Note:** This should be considered on hold and not be merged until we have an agreement on this in #4170.

Commits
-------

9ab1c56 use a global Composer installation
feature #4673 [Reference] add validation config reference section (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
----------

[Reference] add validation config reference section

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Commits
-------

79ad3b5 add validation config reference section
Misc changes
minor #4695 Misc changes (ifdattic)

This PR was squashed before being merged into the 2.3 branch (closes #4695).

Discussion
----------

Misc changes

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3
| Fixed tickets |

Commits
-------

18fa2c6 Misc changes
bug #4707 [Cookbook] Fix XML example for RTE (dunglas)

This PR was merged into the 2.3 branch.

Discussion
----------

[Cookbook] Fix XML example for RTE

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all

Commits
-------

051b5ca [Cookbook] Fix XML example of RTE
Clarify tip for creating a new AppBundle

The previous description was not quite right, since an AppBundle can
also be there in versions before 2.6.