Revise and explain examples

Closes #2468 after most of the work has been done by @uzluisf

doc/Language/exceptions.pod6

@@ -124,18 +124,24 @@ how to return control back to where the exception originated.
 X<|try blocks>
 =head1 C<try> blocks
 
-A C<try> block is a normal block with the L<C<use fatal>
-pragma|/language/pragmas#index-entry-fatal-fatal> turned on and an
-implicit C<CATCH> block that drops the exception, which means you can
-use it to contain them. Caught exceptions are stored inside the C<$!>
-variable, which holds a value of type C<Exception>.
+A C<try> block is a normal block which implicitly turns on the
+L<C<use fatal> pragma|/language/pragmas#index-entry-fatal-fatal> and
+includes an implicit C<CATCH> block that drops the exception, which
+means you can use it to contain them. Caught exceptions are stored
+inside the C<$!> variable, which holds a value of type C<Exception>.
 
-=begin code
+A normal block like this one will simply fail:
+
+=for code
 {
     my $x = +"a";
     say $x.^name;
 } # OUTPUT: «Failure␤»
 
+However, a C<try> block will contain the exception and put it into the
+C<$!> variable:
+
+=begin code
 try {
     my $x = +"a";
     say $x.^name;
@@ -146,7 +152,7 @@ say $!.^name;                     # OUTPUT: «X::Str::Numeric␤»
 =end code
 
 Any exception that is thrown in such a block will be caught by a
-C<CATCH> block, either implicit provided by the user. In the latter
+C<CATCH> block, either implicit or provided by the user. In the latter
 case, any unhandled exception will be rethrown. If you choose not to
 handle the exception, they will be contained by the block.