Add a migration that creates the schedule_joined view

It makes it easier to query this data.

sql/01.views.sql

@@ -0,0 +1,8 @@
+-- Create a view that's easier to query
+CREATE VIEW schedule_joined AS
+  SELECT seg.n   AS title,
+         c.n     AS caster,
+         s.jst   AS jst
+    FROM schedule s
+         JOIN      segment seg ON seg.id = s.segment_id
+         LEFT JOIN caster  c   ON c.id   = s.caster_id;