The page_link_label places the page's URL into the navigation links. If you don't include a page_link_label, the page will not be reachable from default naviagation links. You'll need some other way for users to get to it.
page_link_label
When you try to build the example with:
bigtop -c example.bigtop all
change to the Kids directory and start app.server (note that you might need to build the sqlite database first). Hit the base url:
http://localhost:8080/
And notice the Child link there. If you click on that link, it will take you to the Child controller's page. There you should see the dev navigation pull down menu, which will also include Child.
To install Bigtop, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Bigtop
CPAN shell
perl -MCPAN -e shell install Bigtop
For more information on module installation, please visit the detailed CPAN module installation guide.