Fix docs syntax highlighting errors (#50836)

* Add support for [WARNING]: ...

* Fix unreachable/failed output lexing.

* Detecting retry/--limit lines.

* Removing strange (invisible) characters which cause lexing problems.

* Using better-fitting lexers.

* Improve YAML lexing: don't accept quotes in keys.

* Add Django lexer (unchanged) from Pygments.

* Add support for != and % operators.

docs/docsite/rst/user_guide/playbooks_async.rst

@@ -100,7 +100,7 @@ of tasks running concurrently, you can do it this way::
           - 5
         durations: "{{ item }}"
       include_tasks: execute_batch.yml
-      loop: "{{ sleep_durations | batch(2) | list }}"
+      loop: "{{ sleep_durations | batch(2) | list }}"
 
     #####################
     # execute_batch.yml

docs/docsite/rst/user_guide/playbooks_filters.rst

@@ -904,7 +904,9 @@ style. For example the following::
 
     {{ "Plain style (default)" | comment }}
 
-will produce this output::
+will produce this output:
+
+.. code-block:: text
 
     #
     # Plain style (default)
@@ -923,7 +925,9 @@ above, you can customize it with::
 
   {{ "My Special Case" | comment(decoration="! ") }}
 
-producing::
+producing:
+
+.. code-block:: text
 
   !
   ! My Special Case
@@ -935,7 +939,7 @@ It is also possible to fully customize the comment style::
 
 That will create the following output:
 
-.. code-block:: sh
+.. code-block:: text
 
     #######
     #
@@ -1040,7 +1044,7 @@ To search a string with a regex, use the "regex_search" filter::
     {{ 'ansible' | regex_search('(foobar)') }}
 
     # case insensitive search in multiline mode
-    {{ 'foo\nBAR' | regex_search("^bar", multiline=True, ignorecase=True) }}
+    {{ 'foo\nBAR' | regex_search("^bar", multiline=True, ignorecase=True) }}
 
 
 To search for all occurrences of regex matches, use the "regex_findall" filter::