Fix #2197 extended regex pattern example

docs/content/manual/manual.yml

@@ -2260,7 +2260,7 @@ sections:
 
       To match whitespace in an x pattern use an escape such as \s, e.g.
 
-      * test( "a\\sb", "x" ).
+      * test( "a\\\\sb"; "x" )
 
       Note that certain flags may also be specified within REGEX, e.g.
 

docs/content/manual/v1.5/manual.yml

@@ -1987,7 +1987,7 @@ sections:
 
       To match whitespace in an x pattern use an escape such as \s, e.g.
 
-      * test( "a\\sb", "x" ).
+      * test( "a\\\\sb"; "x" )
 
       Note that certain flags may also be specified within REGEX, e.g.
 

docs/content/manual/v1.6/manual.yml

@@ -2280,7 +2280,7 @@ sections:
 
       To match whitespace in an x pattern use an escape such as \s, e.g.
 
-      * test( "a\\sb", "x" ).
+      * test( "a\\\\sb"; "x" )
 
       Note that certain flags may also be specified within REGEX, e.g.