state: update ProcessState.DB

Add documentation.

1 files changed, 2 insertions, 1 deletions

diff --git a/state/state.go b/state/state.go
index c43071b..c37a74b 100644
--- a/state/state.go
+++ b/state/state.go
@@ -20,7 +20,8 @@ type EntryResult struct {
 }
 
 type ProcessState struct {
-	DB      *db.FernDB
+	// Tracks entries that have already been downloaded.
+	DB *db.FernDB
 	// Channel for Feed.Process goroutines to communicate to the
 	// caller about the number of entries that are being
 	// downloaded for a feed.