Add campaign configuration support

internal/config/defaults.go

@@ -5,6 +5,9 @@ package config
 const (
 	DefaultPipelineConfigPathUsrLocal = "/usr/local/etc/narratio/pipeline.yml"
 	DefaultPipelineConfigPathEtc      = "/etc/narratio/pipeline.yml"
+	DefaultCampaignConfigPathLocal    = "./campaign.yml"
+	DefaultCampaignConfigPathUsrLocal = "/usr/local/etc/narratio/campaign.yml"
+	DefaultCampaignConfigPathEtc      = "/etc/narratio/campaign.yml"
 	DefaultSessionConfigPathLocal     = "./session.yml"
 	DefaultSessionConfigPathUsrLocal  = "/usr/local/etc/narratio/session.yml"
 	DefaultSessionConfigPathEtc       = "/etc/narratio/session.yml"
@@ -88,6 +91,17 @@ var DefaultPipelineConfigSearchPaths = []string{
 	DefaultPipelineConfigPathEtc,
 }
 
+// DefaultCampaignConfigSearchPaths defines the default search order for
+// campaign.yml when callers do not provide an explicit path.
+//
+// Keep this in a variable so future defaults can be extended without changing
+// call sites.
+var DefaultCampaignConfigSearchPaths = []string{
+	DefaultCampaignConfigPathLocal,
+	DefaultCampaignConfigPathUsrLocal,
+	DefaultCampaignConfigPathEtc,
+}
+
 // DefaultSessionConfigSearchPaths defines the default search order for
 // session.yml when callers do not provide an explicit path.
 //