Documented nm/salsa sync

README.Salsa.md

+# Syncing badges on Salsa
+
+If you go to https://salsa.debian.org/enrico you see at the top right a "Debian
+Developer" badge that links to Enrico's nm.d.o page.
+
+Salsa syncs with nm.debian.org using `restricted.views.SalsaExport`.
+
+IIRC we did an initial sync while the Salsa accounts were still aligned with LDAP, 
+and nm.debian.org has salsa information for everyone who was in LDAP at that point.
+
+Since nm.debian.org is (almost) a gatekeeper for LDAP, the information should
+still be valid. "Almost" means that DSA can still create LDAP accounts without
+passing through nm.debian.org, and nm.debian.org would not know anything about
+them, but that happens rarely if at all.