Document lock order acquisition. #116 [ci skip]

api/api.go

@@ -1,2 +1,8 @@
 // Package api provides implementation of aptly REST API
 package api
+
+// Lock order acquisition (canonical):
+//  1. RemoteRepoCollection
+//  2. LocalRepoCollection
+//  3. SnapshotCollection
+//  4. PublishedRepoCollection