build: Include translations in uploaded zip files

The meson port accidentally dropped translations from the generated
zip files for uploading to extensions.gnome.org, add them back.

#69

export-zips.sh

@@ -22,6 +22,7 @@ for f in $extensiondir/*; do
   schema=$schemadir/org.gnome.shell.extensions.$name.gschema.xml
 
   cp $srcdir/NEWS $srcdir/COPYING $f
+  cp -r $localedir $f
 
   if [ -f $schema ]; then
     mkdir $f/schemas