Added a systemd unit and logrotate configuration, packaged in the release

deploy/job-search.logrotate

@@ -0,0 +1,18 @@
+# logrotate configuration for job-search's logs (see README.md, "Rotating
+# the logs"). Install as /etc/logrotate.d/job-search; it is in the release
+# tarball next to the binary.
+#
+# job-search opens its log file once and has no signal to reopen it, so the
+# file is copied and then truncated in place (copytruncate). A line written
+# between the copy and the truncation is lost.
+/var/log/job-search/*.log {
+    weekly
+    rotate 8
+    compress
+    delaycompress
+    missingok
+    notifempty
+    copytruncate
+    # /var/log/job-search belongs to the service user, so rotate as it.
+    su job-search job-search
+}