prefer zef to panda

Closes #894

doc/Language/about.pod6

@@ -34,7 +34,7 @@ Generating this documentation requires:
 =item A recent version of the Rakudo Perl 6 compiler
 
 =item The Perl 6 modules Pod::To::HTML, Pod::To::BigPage, and URI::Escape
-(can be installed via L<panda|https://github.com/tadzik/panda>)
+(can be installed via L<zef|https://github.com/ugexe/zef>).
 
 =item B<Optional>: L<GraphViz|http://graphviz.org>, for creating graphs
 of the relationships between Perl 6 types

doc/Language/faq.pod6

@@ -39,7 +39,7 @@ Mac users can use the latest Rakudo Star DMG binary installer at
 L<http://rakudo.org/downloads/star>
 
 Windows users can use the Rakudo Star MSI binary installer. You will need
-Windows Git and Strawberry Perl 5 to use panda to install library modules.
+Windows Git and Strawberry Perl 5 to use zef to install library modules.
 
 Linux users probably want to download Rakudo Star and follow the compilation
 instructions at L<http://www.perl6.org/downloads/>
@@ -103,7 +103,7 @@ X<|CPAN (FAQ)>X<|ecosystem>
 There isn't yet a module repository for Perl 6 as sophisticated as CPAN. But
 L<modules.perl6.org|https://modules.perl6.org/> has a list of known Perl 6
 modules called the "ecosystem" hosted on github, and
-L<panda|https://github.com/tadzik/panda/> can install those that work with
+L<zef|https://github.com/ugexe/zef/> can install those that work with
 L<rakudo|http://rakudo.org/>.
 
 Support for installing Perl 6 modules from the Perl 5 CPAN is on its way.

doc/Language/variables.pod6

@@ -964,7 +964,7 @@ The C<Grammar.parse> method also sets the caller's C<$/> to the resulting
 L<Match> object.  For the following code:
 
 =begin code :skip-test
-use XML::Grammar; # panda install XML
+use XML::Grammar; # zef install XML
 XML.Grammar.parse("<p>some text</p>");
 say $/;