Clean up repository structure and release docs

sources/app/ReviewState.swift

@@ -0,0 +1,30 @@
+enum ReviewState {
+    static let allStatuses = "All Statuses"
+    static let reviewed = "Reviewed"
+    static let notReviewed = "Not reviewed"
+
+    static func isReviewed(_ status: String) -> Bool {
+        status.localizedCaseInsensitiveCompare("Marked") == .orderedSame
+            || status.localizedCaseInsensitiveCompare(reviewed) == .orderedSame
+    }
+
+    static func label(for status: String) -> String {
+        if isReviewed(status) { return reviewed }
+        return status.localizedCaseInsensitiveCompare("Unmarked") == .orderedSame
+            ? notReviewed
+            : status
+    }
+
+    static func matches(_ status: String, filter: String) -> Bool {
+        switch filter {
+        case allStatuses:
+            return true
+        case reviewed:
+            return isReviewed(status)
+        case notReviewed:
+            return !isReviewed(status)
+        default:
+            return status == filter || label(for: status) == filter
+        }
+    }
+}