cross links to documentation apps are broken

[duncdrum]

for some strange reason links containing {doc} no longer work.
Go to fundocs on exist-db.org (also tested on local). Now select any of the footer or navbar links to the documentation app example Legal in the footer

let's keep the discussion at eXist-db/documentation#154

[duncdrum]

fix for documentation app does not fix clicking on the documentation > documentation here

[tohuuuuu]

It seems to be an issue building the page.html template. When just running mvn compile, the resulting /target/classes/templates/page.html works after copying it into the /db/apps/fundocs/templates collection. But the build process isn't really clear to me, so i'm not sure what's missing with mvn package...