Add PureOS-mirror.list with a basic PureOS setup.

debian/PureOS-mirror.list

+############# config ##################
+#
+# set base_path    /var/spool/apt-mirror
+#
+# set mirror_path  $base_path/mirror
+# set skel_path    $base_path/skel
+# set var_path     $base_path/var
+# set cleanscript $var_path/clean.sh
+# set defaultarch  <running host architecture>
+# set postmirror_script $var_path/postmirror.sh
+# set run_postmirror 0
+set nthreads     20
+set _tilde 0
+#
+############# end config ##############
+
+deb http://repo.puri.sm/pureos @CODENAME@ main
+deb-src http://repo.puri.sm/pureos @CODENAME@ main
+
+clean http://repo.puri.sm/pureos