document the routing issues, since people are noticing and asking

See https://forum.torproject.net/t/tor-metrics-and-torproject-org-are-down/1889

content/issues/2022-01-25-routing-issues.md

+---
+title: routing issues at main provider
+date: 2022-01-25 06:00:00
+resolved: false
+# Possible severity levels: down, disrupted, notice
+severity: disrupted
+affected:
+  - metrics.torproject.org
+  - Tor Check
+  - torproject.org
+  - GitLab
+  - Gitolite
+  - Email
+  - Mailing lists
+section: issue
+---
+
+We are experiencing intermittent network outages that typically
+resolve themselves within a few hours. Preliminary investigations seem
+to point at routing issues at Hetzner, but we have yet to get a solid
+diagnostic. We're following that issue in [issue 40601](https://gitlab.torproject.org/tpo/tpa/team/-/issues/40601).