clean code, and fix errors

src/updates/mod.rs

@@ -0,0 +1,17 @@
+mod settings;
+
+pub use settings::{Settings, Facets};
+
+use serde::{Serialize, Deserialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type")]
+enum UpdateMeta {
+    DocumentsAddition { method: String, format: String },
+    ClearDocuments,
+    Settings(Settings),
+    Facets(Facets),
+}
+
+#[derive(Clone, Debug)]
+pub struct UpdateQueue;