Add (references to) and improve examples

Author: dumarchie

doc/Type/Hash.pod6

@@ -345,8 +345,9 @@ L<named arguments|/type/Capture> and as such won't end up in the C<Hash>:
 Use the corresponding L<subroutine|/language/independent-routines#sub_push> to
 catch this kind of mistake:
 
+    push my %h, f => 7;
     CATCH { default { put .message } };
-    push my %h, f => 7; # OUTPUT: «Unexpected named argument 'f' passed␤»
+    # OUTPUT: «Unexpected named argument 'f' passed␤»
 
 Also note that push can be used as a replacement for assignment during hash
 initialization very useful ways. Take for instance the case of an inverted

doc/Type/independent-routines.pod6

@@ -1177,6 +1177,9 @@ Defined as:
 Calls method L<C<pop>|/routine/pop> on the container, which is supposed to
 remove and return the last element, or fail if the container is empty.
 
+See the documentation of the L<C<Array> method|/type/Array#method_pop> for an
+example.
+
 =head2 sub shift
 
 Defined as:
@@ -1186,6 +1189,14 @@ Defined as:
 Calls method L<C<shift>|/routine/shift> on the container which is supposed to
 remove and return the first element, or fail if the container is empty.
 
+Example:
+
+    my @foo = <a b>;
+    while my $value = shift @foo {
+        say $value;
+    }
+    # OUTPUT: «a␤b␤»
+
 =head2 sub push
 
 Defined as:
@@ -1202,6 +1213,9 @@ add C<b> or the values in C<|@b> to the end of an array. If C<b> is a C<Slip>,
 the container is supposed to add the values produced by
 L<C<b.iterator>|/routine/iterator>.
 
+See the documentation of the L<C<Hash> method|/type/Hash#method_push> for an
+example where the subroutine form is useful.
+
 =head2 sub append
 
 Defined as:
@@ -1224,9 +1238,10 @@ values of a C<Hash>. Whereas L<method append|/type/Hash#method_append> will
 silently ignore literal pairs that are interpreted as named arguments, sub
 C<append> will throw:
 
-    CATCH { default { put .message } };
     my %h = i => 0;
-    append %h, i => (1, 42); # OUTPUT: «Unexpected named argument 'i' passed␤»
+    append %h, i => (1, 42);
+    CATCH { default { put .message } };
+    # OUTPUT: «Unexpected named argument 'i' passed␤»
 
 =head1 Control routines