systemd: Add timers and services to keep git repos up-to-date

Yes, systemd. In my user repo. It's awesome.

.config/systemd/user/proj-fetch.service

@@ -0,0 +1,9 @@
+# vim:ft=systemd:
+[Unit]
+Description=Project fetch service
+
+[Service]
+ExecStart=find %h/Projects -type d -iname .git -execdir git fetch \;
+
+[Install]
+WantedBy=default.target