remove trailing whitespace

Author: coke

doc/Language/faq.pod6

@@ -314,14 +314,14 @@ not. The C<s///> operator works on a variable, into which it puts a newly
 created string object. Likewise, C<$i++> works on the C<$i> variable, not
 just on the value in it.
 
-Knowing this, you would not try to change a literal string (e.g. like 
+Knowing this, you would not try to change a literal string (e.g. like
 C<'hello' ~~ s/h/H/; #doesn't work>), but you might accidentally do
 something equivalent using `map`:
 
     my @foo = <hello world>.map: { s/h/H/ }; # dies with
                                              # Cannot modify an immutable Str (hello)
 
-    my @bar = <hello world>».subst-mutate: 'h', 'H'; # dies with 
+    my @bar = <hello world>».subst-mutate: 'h', 'H'; # dies with
                                                      # Cannot resolve caller subst-mutate(Str: Str, Str);
                                                      # the following candidates match the type but require
                                                      # mutable arguments: ...
@@ -331,7 +331,7 @@ the the original in place:
 
     my @foo = <hello world>.map: { S/h/H/ };  # ['Hello','world']
     my @bar = <hello world>».subst: 'h', 'H'; # ['Hello','world']
-    
+
 See the documentation on L<containers|/language/containers> for more
 information.