Revert "make searchable"

This reverts commit 897f15e.

Author: lizmat

doc/Language/5to6-nutshell.pod

@@ -1205,7 +1205,7 @@ Perl modules is C<PERL5LIB>.
     $ PERL5LIB="/some/module/lib" perl program.pl
 
 In Perl 6 this is similar, one merely needs to change a number!  As you
-probably guessed, you just need to use C<X<PERL6LIB>>:
+probably guessed, you just need to use C<PERL6LIB>:
 
     $ PERL6LIB="/some/module/lib" perl6 program.p6