Merge branch '5.1' into 5.x

* 5.1:
  add a note about npm commands equivalent to yarn's
  Fix: DOCtor-RST
  Enhancement: New rules for DOCtor-RST.
  [#14421] Merged the new description into the current sentence
  Adding more information about default translation domain 'messages'

Author: javiereguiluz

.doctor-rst.yaml

@@ -25,6 +25,8 @@ rules:
     no_namespace_after_use_statements: ~
     no_php_open_tag_in_code_block_php_directive: ~
     no_space_before_self_xml_closing_tag: ~
+    only_backslashes_in_namespace_in_php_code_block: ~
+    only_backslashes_in_use_statements_in_php_code_block: ~
     ordered_use_statements: ~
     php_prefix_before_bin_console: ~
     replace_code_block_types: ~

frontend/encore/simple-example.rst

@@ -63,12 +63,18 @@ To build the assets, run:
 
     # compile assets once
     $ yarn encore dev
+    # if you prefer npm, run:
+    $ npm run dev
 
     # or, recompile assets automatically when files change
     $ yarn encore dev --watch
+    # if you prefer npm, run:
+    $ npm run watch
 
     # on deploy, create a production build
     $ yarn encore production
+    # if you prefer npm, run:
+    $ npm run build
 
 .. note::
 

service_container/tags.rst

@@ -643,7 +643,7 @@ tags, is to implement the static ``getDefaultPriority()`` method on the
 service itself::
 
     // src/Handler/One.php
-    namespace App/Handler;
+    namespace App\Handler;
 
     class One
     {

translation.rst

@@ -408,9 +408,10 @@ priority message files.
 The filename of the translation files is also important: each message file
 must be named according to the following path: ``domain.locale.loader``:
 
-* **domain**: An optional way to organize messages into groups. Unless
+* **domain**: Domains are a way to organize messages into groups. Unless
   parts of the application are explicitly separated from each other, it is
-  recommended to only use default ``messages`` domain;
+  recommended to only use the default ``messages`` domain (e.g.
+  ``messages.en.yaml``).
 
 * **locale**: The locale that the translations are for (e.g. ``en_GB``, ``en``, etc);